Phase 2e (0.6.1-beta): drop legacy upstream/downstream tables

The file_holders table is now the only tracker of per-file peer
relationships. post_upstream, post_downstream, blob_upstream, and
blob_downstream are dropped at first launch after the seed migration
copies any existing entries.

Schema:
- DROP TABLE IF EXISTS on all four legacy tables after seeding
- Seed migration guards with sqlite_master table_exists check so fresh
  installs don't crash trying to read non-existent sources
- Remove CREATE TABLE statements for the four tables from init
- Remove Protocol v4 Phase 6 post_upstream priority migration (dead)
- Remove blob_upstream preferred_tree column migration (dead)

Rust:
- Remove add/get/remove post_upstream, post_downstream,
  blob_upstream, blob_downstream methods
- Remove get_blob_upstream_preferred_tree / update variant
- Rewrite get_eviction_candidates's downstream_count subquery to
  count file_holders entries
- Rewrite apply_delete's cascade cleanup to clear file_holders
  instead of post_upstream/post_downstream
- cleanup_cdn_for_blob now clears file_holders for the CID

Callers:
- All dual-write sites in connection.rs and node.rs now do
  touch_file_holder only (legacy writes removed)
- get_stale_manifests replaced with get_stale_manifest_cids; caller
  in node.rs picks a refresh source from file_holders

Tests:
- Remove blob_upstream_crud, blob_downstream_crud_and_limit,
  blob_upstream_preferred_tree, remove_blob_upstream,
  post_downstream_crud
- Add file_holders_lru_cap and file_holders_direction_promotion tests

All 110 core tests passing. Workspace compiles clean.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

crates/core/src/connection.rs

@@ -1393,8 +1393,12 @@ impl ConnectionManager {
         {
             let s = storage.get().await;
             for pid in &new_post_ids {
-                let prio = s.get_post_upstreams(pid).map(|v| v.len() as u8).unwrap_or(0);
-                let _ = s.add_post_upstream(pid, peer_id, prio);
+                let _ = s.touch_file_holder(
+                    pid,
+                    peer_id,
+                    &[],
+                    crate::storage::HolderDirection::Received,
+                );
             }
             for author in &synced_authors {
                 let _ = s.update_follow_last_sync(author, now_ms);
@@ -1940,8 +1944,12 @@ impl ConnectionManager {
         {
             let storage = self.storage.get().await;
             for pid in &new_post_ids {
-                let prio = storage.get_post_upstreams(pid).map(|v| v.len() as u8).unwrap_or(0);
-                let _ = storage.add_post_upstream(pid, from, prio);
+                let _ = storage.touch_file_holder(
+                    pid,
+                    from,
+                    &[],
+                    crate::storage::HolderDirection::Received,
+                );
             }
             for author in &synced_authors {
                 let _ = storage.update_follow_last_sync(author, now_ms);
@@ -2034,8 +2042,12 @@ impl ConnectionManager {
         {
             let storage = self.storage.get().await;
             for pid in &new_post_ids {
-                let prio = storage.get_post_upstreams(pid).map(|v| v.len() as u8).unwrap_or(0);
-                let _ = storage.add_post_upstream(pid, peer_id, prio);
+                let _ = storage.touch_file_holder(
+                    pid,
+                    peer_id,
+                    &[],
+                    crate::storage::HolderDirection::Received,
+                );
             }
             for author in &synced_authors {
                 let _ = storage.update_follow_last_sync(author, now_ms);
@@ -2810,13 +2822,9 @@ impl ConnectionManager {
                 if store.get_post_with_visibility(post_id).ok().flatten().is_some() {
                     Some(self.our_node_id)
                 } else {
-                    // CDN tree: do any of our downstream hosts have it?
-                    let downstream = store.get_post_downstream(post_id).unwrap_or_default();
-                    if !downstream.is_empty() {
-                        Some(downstream[0])
-                    } else {
-                        None
-                    }
+                    // Any known holder of this post?
+                    let holders = store.get_file_holders(post_id).unwrap_or_default();
+                    holders.first().map(|(nid, _)| *nid)
                 }
             };
             post_holder = found;
@@ -2830,9 +2838,9 @@ impl ConnectionManager {
                 // Check CDN: do we know who has it via blob post ownership?
                 let store = self.storage.get().await;
                 if let Ok(Some(pid)) = store.get_blob_post_id(blob_id) {
-                    let downstream = store.get_post_downstream(&pid).unwrap_or_default();
-                    if !downstream.is_empty() {
-                        blob_holder = Some(downstream[0]);
+                    let holders = store.get_file_holders(&pid).unwrap_or_default();
+                    if let Some((nid, _)) = holders.first() {
+                        blob_holder = Some(*nid);
                     }
                 }
             }
@@ -4871,7 +4879,7 @@ impl ConnectionManager {
                 let cm = conn_mgr.lock().await;
 
                 // Collect blob CIDs + CDN peers before async work
-                let mut blob_cleanup: Vec<([u8; 32], Vec<(NodeId, Vec<String>)>, Option<(NodeId, Vec<String>)>)> = Vec::new();
+                let mut blob_cleanup: Vec<([u8; 32], Vec<(NodeId, Vec<String>)>)> = Vec::new();
                 {
                     let storage = cm.storage.get().await;
                     for dr in &payload.records {
@@ -4879,9 +4887,8 @@ impl ConnectionManager {
                             // Collect blobs for CDN cleanup before deleting
                             let blob_cids = storage.get_blobs_for_post(&dr.post_id).unwrap_or_default();
                             for cid in blob_cids {
-                                let downstream = storage.get_blob_downstream(&cid).unwrap_or_default();
-                                let upstream = storage.get_blob_upstream(&cid).ok().flatten();
-                                blob_cleanup.push((cid, downstream, upstream));
+                                let holders = storage.get_file_holders(&cid).unwrap_or_default();
+                                blob_cleanup.push((cid, holders));
                             }
                             let _ = storage.store_delete(dr);
                             let _ = storage.apply_delete(dr);
@@ -4897,18 +4904,11 @@ impl ConnectionManager {
 
                 // Gather connections for CDN delete notices under lock, then send outside
                 let mut delete_notices: Vec<(iroh::endpoint::Connection, crate::protocol::BlobDeleteNoticePayload)> = Vec::new();
-                for (cid, downstream, upstream) in &blob_cleanup {
-                    let upstream_info = upstream.as_ref().map(|(nid, addrs)| PeerWithAddress { n: hex::encode(nid), a: addrs.clone() });
-                    let ds_payload = crate::protocol::BlobDeleteNoticePayload { cid: *cid, upstream_node: upstream_info };
-                    for (ds_nid, _) in downstream {
-                        if let Some(pc) = cm.connections_ref().get(ds_nid) {
-                            delete_notices.push((pc.connection.clone(), ds_payload.clone()));
-                        }
-                    }
-                    if let Some((up_nid, _)) = upstream {
-                        let up_payload = crate::protocol::BlobDeleteNoticePayload { cid: *cid, upstream_node: None };
-                        if let Some(pc) = cm.connections_ref().get(up_nid) {
-                            delete_notices.push((pc.connection.clone(), up_payload));
+                for (cid, holders) in &blob_cleanup {
+                    let payload = crate::protocol::BlobDeleteNoticePayload { cid: *cid, upstream_node: None };
+                    for (peer, _addrs) in holders {
+                        if let Some(pc) = cm.connections_ref().get(peer) {
+                            delete_notices.push((pc.connection.clone(), payload.clone()));
                         }
                     }
                 }
@@ -4958,24 +4958,38 @@ impl ConnectionManager {
             }
             MessageType::PostPush => {
                 let push: PostPushPayload = read_payload(recv, MAX_PAYLOAD).await?;
-                let cm = conn_mgr.lock().await;
-                let storage = cm.storage.get().await;
-                if !storage.is_deleted(&push.post.id)?
-                    && storage.get_post(&push.post.id)?.is_none()
-                    && crate::content::verify_post_id(&push.post.id, &push.post.post)
-                {
-                    let _ = storage.store_post_with_visibility(
-                        &push.post.id,
-                        &push.post.post,
-                        &push.post.visibility,
-                    );
-                    let prio = storage.get_post_upstreams(&push.post.id).map(|v| v.len() as u8).unwrap_or(0);
-                    let _ = storage.add_post_upstream(&push.post.id, &remote_node_id, prio);
-                    info!(
+                // Encrypted posts are no longer accepted via direct push — they propagate
+                // via the CDN to eliminate the sender→recipient traffic signal.
+                if !matches!(push.post.visibility, crate::types::PostVisibility::Public) {
+                    debug!(
                         peer = hex::encode(remote_node_id),
                         post_id = hex::encode(push.post.id),
-                        "Received direct post push"
+                        "Ignoring non-public PostPush"
                     );
+                } else {
+                    let cm = conn_mgr.lock().await;
+                    let storage = cm.storage.get().await;
+                    if !storage.is_deleted(&push.post.id)?
+                        && storage.get_post(&push.post.id)?.is_none()
+                        && crate::content::verify_post_id(&push.post.id, &push.post.post)
+                    {
+                        let _ = storage.store_post_with_visibility(
+                            &push.post.id,
+                            &push.post.post,
+                            &push.post.visibility,
+                        );
+                        let _ = storage.touch_file_holder(
+                            &push.post.id,
+                            &remote_node_id,
+                            &[],
+                            crate::storage::HolderDirection::Received,
+                        );
+                        info!(
+                            peer = hex::encode(remote_node_id),
+                            post_id = hex::encode(push.post.id),
+                            "Received direct post push"
+                        );
+                    }
                 }
             }
             MessageType::AudienceRequest => {
@@ -5063,17 +5077,24 @@ impl ConnectionManager {
                         &entry.manifest.author_manifest.author,
                         entry.manifest.author_manifest.updated_at,
                     );
+                    // Remote peer pushed us this manifest → they hold the file.
+                    let _ = storage.touch_file_holder(
+                        &entry.cid,
+                        &remote_node_id,
+                        &[],
+                        crate::storage::HolderDirection::Received,
+                    );
                     stored_entries.push(entry.clone());
                 }
-                // Gather downstream peers for relay before dropping locks
+                // Gather file holders for relay before dropping locks
                 let mut relay_targets: Vec<(NodeId, crate::protocol::ManifestPushPayload)> = Vec::new();
                 for entry in &stored_entries {
-                    let downstream = storage.get_blob_downstream(&entry.cid).unwrap_or_default();
-                    for (ds_nid, _) in downstream {
-                        if ds_nid == remote_node_id {
+                    let holders = storage.get_file_holders(&entry.cid).unwrap_or_default();
+                    for (peer, _addrs) in holders {
+                        if peer == remote_node_id {
                             continue;
                         }
-                        relay_targets.push((ds_nid, crate::protocol::ManifestPushPayload {
+                        relay_targets.push((peer, crate::protocol::ManifestPushPayload {
                             manifests: vec![entry.clone()],
                         }));
                     }
@@ -5176,8 +5197,12 @@ impl ConnectionManager {
                                             let cm = cm_arc.lock().await;
                                             let storage = cm.storage.get().await;
                                             if storage.store_post_with_visibility(&sync_post.id, &sync_post.post, &sync_post.visibility).unwrap_or(false) {
-                                                let prio = storage.get_post_upstreams(&sync_post.id).map(|v| v.len() as u8).unwrap_or(0);
-                                                let _ = storage.add_post_upstream(&sync_post.id, &sender_id, prio);
+                                                let _ = storage.touch_file_holder(
+                                                    &sync_post.id,
+                                                    &sender_id,
+                                                    &[],
+                                                    crate::storage::HolderDirection::Received,
+                                                );
                                                 let now = std::time::SystemTime::now()
                                                     .duration_since(std::time::UNIX_EPOCH)
                                                     .unwrap_or_default()
@@ -5268,32 +5293,14 @@ impl ConnectionManager {
                 let storage = cm.storage.get().await;
                 let cid = payload.cid;
 
-                // Check if sender was our upstream for this blob
-                let was_upstream = storage.get_blob_upstream(&cid).ok().flatten()
-                    .map(|(nid, _)| nid == remote_node_id)
-                    .unwrap_or(false);
-
-                if was_upstream {
-                    // Sender was our upstream — clear it
-                    let _ = storage.remove_blob_upstream(&cid);
-
-                    // If they provided their upstream, store it as our new upstream
-                    if let Some(ref new_up) = payload.upstream_node {
-                        if let Ok(nid_bytes) = hex::decode(&new_up.n) {
-                            if let Ok(nid) = <[u8; 32]>::try_from(nid_bytes.as_slice()) {
-                                let _ = storage.store_blob_upstream(&cid, &nid, &new_up.a);
-                            }
-                        }
-                    }
-                } else {
-                    // Sender was our downstream — remove them
-                    let _ = storage.remove_blob_downstream(&cid, &remote_node_id);
-                }
+                // Flat-holder model: drop the sender as a holder of this file.
+                // The author's DeleteRecord (separate signed message) is what
+                // triggers the actual blob removal for followers.
+                let _ = storage.remove_file_holder(&cid, &remote_node_id);
 
                 info!(
                     peer = hex::encode(remote_node_id),
                     cid = hex::encode(cid),
-                    was_upstream,
                     "Received blob delete notice"
                 );
             }
@@ -5437,7 +5444,12 @@ impl ConnectionManager {
                 let payload: PostDownstreamRegisterPayload = read_payload(recv, MAX_PAYLOAD).await?;
                 let cm = conn_mgr.lock().await;
                 let storage = cm.storage.get().await;
-                let _ = storage.add_post_downstream(&payload.post_id, &remote_node_id);
+                let _ = storage.touch_file_holder(
+                    &payload.post_id,
+                    &remote_node_id,
+                    &[],
+                    crate::storage::HolderDirection::Sent,
+                );
                 drop(storage);
                 trace!(
                     peer = hex::encode(remote_node_id),
@@ -5692,15 +5704,28 @@ impl ConnectionManager {
                             let storage = storage.get().await;
                             let manifest: Option<crate::types::CdnManifest> = storage.get_cdn_manifest(&payload.cid).ok().flatten().and_then(|json| {
                                 if let Ok(am) = serde_json::from_str::<crate::types::AuthorManifest>(&json) {
-                                    let ds_count = storage.get_blob_downstream_count(&payload.cid).unwrap_or(0);
+                                    let ds_count = storage.get_file_holder_count(&payload.cid).unwrap_or(0);
                                     Some(crate::types::CdnManifest { author_manifest: am, host: our_node_id, host_addresses: vec![], source: our_node_id, source_addresses: vec![], downstream_count: ds_count })
                                 } else { serde_json::from_str(&json).ok() }
                             });
                             let (cdn_registered, cdn_redirect_peers) = if !payload.requester_addresses.is_empty() {
-                                let ok = storage.add_blob_downstream(&payload.cid, &remote_node_id, &payload.requester_addresses).unwrap_or(false);
-                                if ok { (true, vec![]) } else {
-                                    let downstream = storage.get_blob_downstream(&payload.cid).unwrap_or_default();
-                                    let redirects: Vec<PeerWithAddress> = downstream.into_iter().map(|(nid, addrs)| PeerWithAddress { n: hex::encode(nid), a: addrs }).collect();
+                                let prior_count = storage.get_file_holder_count(&payload.cid).unwrap_or(0);
+                                let _ = storage.touch_file_holder(
+                                    &payload.cid,
+                                    &remote_node_id,
+                                    &payload.requester_addresses,
+                                    crate::storage::HolderDirection::Sent,
+                                );
+                                // If we already had 5 holders before adding this one, the
+                                // requester should consult them too for CDN lookups.
+                                if prior_count < 5 {
+                                    (true, vec![])
+                                } else {
+                                    let holders = storage.get_file_holders(&payload.cid).unwrap_or_default();
+                                    let redirects: Vec<PeerWithAddress> = holders.into_iter()
+                                        .filter(|(nid, _)| *nid != remote_node_id)
+                                        .map(|(nid, addrs)| PeerWithAddress { n: hex::encode(nid), a: addrs })
+                                        .collect();
                                     (false, redirects)
                                 }
                             } else { (false, vec![]) };
@@ -5727,7 +5752,7 @@ impl ConnectionManager {
                         Some(json) => {
                             let manifest = if let Ok(am) = serde_json::from_str::<crate::types::AuthorManifest>(&json) {
                                 if am.updated_at > payload.current_updated_at {
-                                    let ds_count = store.get_blob_downstream_count(&payload.cid).unwrap_or(0);
+                                    let ds_count = store.get_file_holder_count(&payload.cid).unwrap_or(0);
                                     Some(crate::types::CdnManifest { author_manifest: am, host: our_node_id, host_addresses: vec![], source: our_node_id, source_addresses: vec![], downstream_count: ds_count })
                                 } else { None }
                             } else { None };
@@ -6072,9 +6097,14 @@ impl ConnectionManager {
                         to_pull.push(*pid);
                     }
 
-                    // Register as downstream for all accepted posts
+                    // Register as holder for all accepted posts
                     for pid in &acc {
-                        let _ = storage.add_post_downstream(pid, &remote_node_id);
+                        let _ = storage.touch_file_holder(
+                            pid,
+                            &remote_node_id,
+                            &[],
+                            crate::storage::HolderDirection::Sent,
+                        );
                     }
 
                     (acc, rej, to_pull)
@@ -6125,8 +6155,12 @@ impl ConnectionManager {
                                     let cm = cm_arc.lock().await;
                                     let storage = cm.storage.get().await;
                                     let _ = storage.store_post_with_visibility(&sp.id, &sp.post, &sp.visibility);
-                                    let prio = storage.get_post_upstreams(&sp.id).map(|v| v.len() as u8).unwrap_or(0);
-                                    let _ = storage.add_post_upstream(&sp.id, &sender, prio);
+                                    let _ = storage.touch_file_holder(
+                                        &sp.id,
+                                        &sender,
+                                        &[],
+                                        crate::storage::HolderDirection::Received,
+                                    );
                                     let blob_store = cm.blob_store.clone();
                                     drop(storage);
                                     drop(cm);
@@ -6153,7 +6187,12 @@ impl ConnectionManager {
                                                 let cm = cm_arc.lock().await;
                                                 let storage = cm.storage.get().await;
                                                 let _ = storage.record_blob(&att.cid, post_id, &post_author, data.len() as u64, &att.mime_type, att.size_bytes);
-                                                let _ = storage.add_post_upstream(&att.cid, &sender, 0);
+                                                let _ = storage.touch_file_holder(
+                                                    &att.cid,
+                                                    &sender,
+                                                    &[],
+                                                    crate::storage::HolderDirection::Received,
+                                                );
                                             }
                                             Ok(())
                                         }.await;
@@ -6178,12 +6217,14 @@ impl ConnectionManager {
         Ok(())
     }
 
-    /// Handle an incoming BlobHeaderDiff — store engagement ops and re-propagate to downstream + upstream.
+    /// Handle an incoming BlobHeaderDiff — store engagement ops and re-propagate
+    /// to the post's file_holders (flat set, up to 5 most recent).
     async fn handle_blob_header_diff(&self, payload: BlobHeaderDiffPayload, sender: NodeId) {
         use crate::types::BlobHeaderDiffOp;
 
-        // Gather policy + audience data, then drop lock immediately
-        let (policy, approved_audience, downstream, upstreams) = {
+        // Gather policy + audience data + holders, then drop lock immediately.
+        // Remote peer clearly holds this post — record them as a holder.
+        let (policy, approved_audience, holders) = {
             let storage = self.storage.get().await;
             let policy = storage.get_comment_policy(&payload.post_id)
                 .ok()
@@ -6193,13 +6234,18 @@ impl ConnectionManager {
                 crate::types::AudienceDirection::Inbound,
                 Some(crate::types::AudienceStatus::Approved),
             ).unwrap_or_default();
-            let downstream = storage.get_post_downstream(&payload.post_id).unwrap_or_default();
-            let upstreams: Vec<NodeId> = storage.get_post_upstreams(&payload.post_id)
+            let _ = storage.touch_file_holder(
+                &payload.post_id,
+                &sender,
+                &[],
+                crate::storage::HolderDirection::Received,
+            );
+            let holders: Vec<NodeId> = storage.get_file_holders(&payload.post_id)
                 .unwrap_or_default()
                 .into_iter()
-                .map(|(nid, _)| nid)
+                .map(|(nid, _addrs)| nid)
                 .collect();
-            (policy, approved, downstream, upstreams)
+            (policy, approved, holders)
         };
 
         // Filter ops using gathered data (no lock held)
@@ -6381,26 +6427,16 @@ impl ConnectionManager {
             let _ = storage.update_post_last_engagement(&payload.post_id, payload.timestamp_ms);
         }
 
-        // Collect all targets (downstream + all upstreams), then send in a single batched task
+        // Re-propagate to all file holders (flat set, max 5). Exclude sender.
         let mut targets: Vec<iroh::endpoint::Connection> = Vec::new();
-        for peer_id in downstream {
-            if peer_id == sender { continue; }
-            if let Some(conn) = self.connections.get(&peer_id).map(|mc| mc.connection.clone())
-                .or_else(|| self.sessions.get(&peer_id).map(|sc| sc.connection.clone()))
+        for peer_id in &holders {
+            if *peer_id == sender { continue; }
+            if let Some(conn) = self.connections.get(peer_id).map(|mc| mc.connection.clone())
+                .or_else(|| self.sessions.get(peer_id).map(|sc| sc.connection.clone()))
             {
                 targets.push(conn);
             }
         }
-        // Phase 6: Try all upstreams, not just one
-        for up in &upstreams {
-            if *up != sender {
-                if let Some(conn) = self.connections.get(up).map(|mc| mc.connection.clone())
-                    .or_else(|| self.sessions.get(up).map(|sc| sc.connection.clone()))
-                {
-                    targets.push(conn);
-                }
-            }
-        }
         if !targets.is_empty() {
             let payload_clone = payload.clone();
             tokio::spawn(async move {
@@ -7684,8 +7720,8 @@ impl ConnectionActor {
             if s.get_post_with_visibility(post_id).ok().flatten().is_some() {
                 post_holder = Some(ctx.our_node_id);
             } else {
-                let downstream = s.get_post_downstream(post_id).unwrap_or_default();
-                if !downstream.is_empty() { post_holder = Some(downstream[0]); }
+                let holders = s.get_file_holders(post_id).unwrap_or_default();
+                if let Some((nid, _)) = holders.first() { post_holder = Some(*nid); }
             }
         }
 
@@ -7695,8 +7731,8 @@ impl ConnectionActor {
             } else {
                 let s = ctx.storage.get().await;
                 if let Ok(Some(pid)) = s.get_blob_post_id(blob_id) {
-                    let downstream = s.get_post_downstream(&pid).unwrap_or_default();
-                    if !downstream.is_empty() { blob_holder = Some(downstream[0]); }
+                    let holders = s.get_file_holders(&pid).unwrap_or_default();
+                    if let Some((nid, _)) = holders.first() { blob_holder = Some(*nid); }
                 }
             }
         }

crates/core/src/http.rs

@@ -378,7 +378,11 @@ async fn try_redirect(
             Ok(Some((_, PostVisibility::Public))) => {}
             _ => return false, // not found or not public — hard close
         }
-        store.get_post_downstream(post_id).unwrap_or_default()
+        store.get_file_holders(post_id)
+            .unwrap_or_default()
+            .into_iter()
+            .map(|(nid, _addrs)| nid)
+            .collect::<Vec<_>>()
     };
 
     // Get addresses for downstream peers

crates/core/src/network.rs

@@ -902,50 +902,6 @@ impl Network {
         self.send_to_audience(MessageType::PostNotification, &payload).await
     }
 
-    /// Push a full post directly to recipients (persistent if available, ephemeral otherwise).
-    pub async fn push_post_to_recipients(
-        &self,
-        post_id: &crate::types::PostId,
-        post: &Post,
-        visibility: &PostVisibility,
-    ) -> usize {
-        let recipients: Vec<NodeId> = match visibility {
-            PostVisibility::Public => return 0,
-            PostVisibility::Encrypted { recipients } => {
-                recipients.iter().map(|wk| wk.recipient).collect()
-            }
-            PostVisibility::GroupEncrypted { group_id, .. } => {
-                // Push to all group members
-                match self.storage.get().await.get_all_group_members() {
-                    Ok(map) => map.get(group_id).cloned().unwrap_or_default().into_iter().collect(),
-                    Err(_) => return 0,
-                }
-            }
-        };
-
-        let payload = PostPushPayload {
-            post: SyncPost {
-                id: *post_id,
-                post: post.clone(),
-                visibility: visibility.clone(),
-            },
-        };
-
-        let mut pushed = 0;
-        for recipient in &recipients {
-            if self.send_to_peer_uni(recipient, MessageType::PostPush, &payload).await.is_ok() {
-                pushed += 1;
-                debug!(
-                    recipient = hex::encode(recipient),
-                    post_id = hex::encode(post_id),
-                    "Pushed post to recipient"
-                );
-            }
-        }
-
-        pushed
-    }
-
     /// Push a profile update to all audience members (ephemeral-capable).
     pub async fn push_profile(&self, profile: &PublicProfile) -> usize {
         // Sanitize: if public_visible=false, strip display_name/bio from pushed profile
@@ -1059,15 +1015,16 @@ impl Network {
         sent
     }
 
-    /// Push updated manifests to all downstream peers for a given CID.
+    /// Push an updated manifest to all known holders of the file (flat set,
+    /// up to 5 most-recent). Replaces the legacy downstream-tree push.
     pub async fn push_manifest_to_downstream(
         &self,
         cid: &[u8; 32],
         manifest: &crate::types::CdnManifest,
     ) -> usize {
-        let downstream = {
+        let holders = {
             let storage = self.storage.get().await;
-            storage.get_blob_downstream(cid).unwrap_or_default()
+            storage.get_file_holders(cid).unwrap_or_default()
         };
         let payload = crate::protocol::ManifestPushPayload {
             manifests: vec![crate::protocol::ManifestPushEntry {
@@ -1076,54 +1033,40 @@ impl Network {
             }],
         };
         let mut sent = 0;
-        for (ds_nid, _) in &downstream {
-            if self.send_to_peer_uni(ds_nid, MessageType::ManifestPush, &payload).await.is_ok() {
+        for (peer, peer_addrs) in &holders {
+            if self.send_to_peer_uni(peer, MessageType::ManifestPush, &payload).await.is_ok() {
                 sent += 1;
+                let storage = self.storage.get().await;
+                let _ = storage.touch_file_holder(
+                    cid,
+                    peer,
+                    peer_addrs,
+                    crate::storage::HolderDirection::Sent,
+                );
             }
         }
         sent
     }
 
-    /// Send blob delete notices to downstream and upstream peers.
-    /// Downstream peers receive our upstream info for tree healing.
-    /// Upstream peers receive no upstream info (just "remove me as downstream").
+    /// Send blob delete notices to all known holders of a file.
+    /// Second argument kept as Option for signature stability; flat-holder
+    /// model doesn't need separate upstream handling.
     pub async fn send_blob_delete_notices(
         &self,
         cid: &[u8; 32],
-        downstream: &[(NodeId, Vec<String>)],
-        upstream: Option<&(NodeId, Vec<String>)>,
+        holders: &[(NodeId, Vec<String>)],
+        _legacy_upstream: Option<&(NodeId, Vec<String>)>,
     ) -> usize {
-        let upstream_info = upstream.map(|(nid, addrs)| {
-            crate::types::PeerWithAddress {
-                n: hex::encode(nid),
-                a: addrs.clone(),
-            }
-        });
-
-        let mut sent = 0;
-
-        // Notify downstream (with upstream info for tree healing)
-        let ds_payload = crate::protocol::BlobDeleteNoticePayload {
+        let payload = crate::protocol::BlobDeleteNoticePayload {
             cid: *cid,
-            upstream_node: upstream_info,
+            upstream_node: None,
         };
-        for (ds_nid, _) in downstream {
-            if self.send_to_peer_uni(ds_nid, MessageType::BlobDeleteNotice, &ds_payload).await.is_ok() {
+        let mut sent = 0;
+        for (peer, _addrs) in holders {
+            if self.send_to_peer_uni(peer, MessageType::BlobDeleteNotice, &payload).await.is_ok() {
                 sent += 1;
             }
         }
-
-        // Notify upstream (no upstream info)
-        if let Some((up_nid, _)) = upstream {
-            let up_payload = crate::protocol::BlobDeleteNoticePayload {
-                cid: *cid,
-                upstream_node: None,
-            };
-            if self.send_to_peer_uni(up_nid, MessageType::BlobDeleteNotice, &up_payload).await.is_ok() {
-                sent += 1;
-            }
-        }
-
         sent
     }
 
@@ -2356,24 +2299,24 @@ impl Network {
         self.endpoint.close().await;
     }
 
-    /// Propagate an engagement diff to all downstream holders of a post (CDN tree).
-    /// Excludes the sender to avoid loops.
+    /// Propagate an engagement diff to all known holders of a post (flat set,
+    /// up to 5 most-recent). Excludes the sender to avoid loops.
     pub async fn propagate_engagement_diff(
         &self,
         post_id: &crate::types::PostId,
         payload: &crate::protocol::BlobHeaderDiffPayload,
         exclude_peer: &crate::types::NodeId,
     ) -> usize {
-        let downstream = {
+        let holders = {
             let storage = self.storage.get().await;
-            storage.get_post_downstream(post_id).unwrap_or_default()
+            storage.get_file_holders(post_id).unwrap_or_default()
         };
         let mut sent = 0;
-        for ds_nid in &downstream {
-            if ds_nid == exclude_peer {
+        for (peer, _addrs) in &holders {
+            if peer == exclude_peer {
                 continue;
             }
-            if self.send_to_peer_uni(ds_nid, MessageType::BlobHeaderDiff, payload).await.is_ok() {
+            if self.send_to_peer_uni(peer, MessageType::BlobHeaderDiff, payload).await.is_ok() {
                 sent += 1;
             }
         }

crates/core/src/node.rs

@@ -836,13 +836,12 @@ impl Node {
             }
         }
 
-        // For encrypted posts, push directly to recipients
-        let pushed = self.network.push_post_to_recipients(&post_id, &post, &visibility).await;
-
-        // For public posts, push to audience members
+        // For public posts, push to audience members. Encrypted posts propagate
+        // via the CDN (ManifestPush + header-diff) to eliminate the sender→recipient
+        // traffic signal.
         let audience_pushed = self.network.push_to_audience(&post_id, &post, &visibility).await;
 
-        info!(post_id = hex::encode(post_id), pushed, audience_pushed, "Created new post");
+        info!(post_id = hex::encode(post_id), audience_pushed, "Created new post");
         Ok((post_id, post, visibility))
     }
 
@@ -1351,7 +1350,12 @@ impl Node {
             let source_addrs: Vec<String> = response.manifest.as_ref()
                 .map(|m| m.host_addresses.clone())
                 .unwrap_or_default();
-            let _ = storage.store_blob_upstream(cid, from_peer, &source_addrs);
+            let _ = storage.touch_file_holder(
+                cid,
+                from_peer,
+                &source_addrs,
+                crate::storage::HolderDirection::Received,
+            );
         }
         Ok(data)
     }
@@ -1379,16 +1383,17 @@ impl Node {
         // Collect redirect peers from responses in case we need them later
         let mut redirect_peers: Vec<crate::types::PeerWithAddress> = Vec::new();
 
-        // 2. Try existing upstream (if we previously fetched this blob)
-        let upstream = {
+        // 2. Try known holders (up to 5 most-recent peers we've interacted
+        //    with about this file).
+        let known_holders = {
             let storage = self.storage.get().await;
-            storage.get_blob_upstream(cid)?
+            storage.get_file_holders(cid).unwrap_or_default()
         };
-        if let Some((upstream_nid, _upstream_addrs)) = upstream {
-            match self.fetch_blob_from_peer(cid, &upstream_nid, post_id, author, mime_type, created_at).await {
+        for (holder_nid, _addrs) in &known_holders {
+            match self.fetch_blob_from_peer(cid, holder_nid, post_id, author, mime_type, created_at).await {
                 Ok(Some(data)) => return Ok(Some(data)),
                 Ok(None) => {}
-                Err(e) => warn!(error = %e, "blob fetch from upstream failed"),
+                Err(e) => warn!(error = %e, "blob fetch from known holder failed"),
             }
         }
 
@@ -1413,7 +1418,12 @@ impl Node {
                             let _ = storage.store_cdn_manifest(cid, &author_json, &cdn_manifest.author_manifest.author, cdn_manifest.author_manifest.updated_at);
                         }
                     }
-                    let _ = storage.store_blob_upstream(cid, &lateral, &[]);
+                    let _ = storage.touch_file_holder(
+                        cid,
+                        &lateral,
+                        &[],
+                        crate::storage::HolderDirection::Received,
+                    );
                     return Ok(Some(data));
                 }
                 Ok((None, response)) => {
@@ -1981,14 +1991,13 @@ impl Node {
             signature,
         };
 
-        // Collect blob CIDs + CDN peers before cleanup
+        // Collect blob CIDs + known holders before cleanup (for delete notices)
         let blob_cdn_info: Vec<([u8; 32], Vec<(NodeId, Vec<String>)>, Option<(NodeId, Vec<String>)>)> = {
             let storage = self.storage.get().await;
             let cids = storage.get_blobs_for_post(post_id).unwrap_or_default();
             cids.into_iter().map(|cid| {
-                let downstream = storage.get_blob_downstream(&cid).unwrap_or_default();
-                let upstream = storage.get_blob_upstream(&cid).ok().flatten();
-                (cid, downstream, upstream)
+                let holders = storage.get_file_holders(&cid).unwrap_or_default();
+                (cid, holders, None::<(NodeId, Vec<String>)>)
             }).collect()
         };
 
@@ -2108,12 +2117,10 @@ impl Node {
                     storage.store_post_with_visibility(&new_post_id, &new_post, &new_vis)?;
                 }
 
-                // delete_post already pushes the DeleteRecord
+                // delete_post already pushes the DeleteRecord.
+                // Replacement post propagates via the CDN to remaining recipients.
                 self.delete_post(post_id).await?;
 
-                // Push replacement post directly to remaining recipients
-                self.network.push_post_to_recipients(&new_post_id, &new_post, &new_vis).await;
-
                 info!(
                     old_id = hex::encode(post_id),
                     new_id = hex::encode(new_post_id),
@@ -3086,20 +3093,27 @@ impl Node {
                     .duration_since(std::time::UNIX_EPOCH)
                     .unwrap_or_default()
                     .as_millis() as u64 - max_age_ms;
-                let stale = {
+                let stale_cids = {
                     let s = storage.get().await;
-                    s.get_stale_manifests(cutoff).unwrap_or_default()
+                    s.get_stale_manifest_cids(cutoff).unwrap_or_default()
                 };
-                for (cid, upstream_nid, _upstream_addrs) in &stale {
-                    // Get current updated_at for this manifest
-                    let current_updated_at = {
+                for cid in &stale_cids {
+                    // Get current updated_at + pick a holder to refresh from
+                    let (current_updated_at, refresh_source) = {
                         let s = storage.get().await;
-                        s.get_cdn_manifest(cid).ok().flatten()
+                        let updated_at = s.get_cdn_manifest(cid).ok().flatten()
                             .and_then(|json| serde_json::from_str::<crate::types::AuthorManifest>(&json).ok())
                             .map(|m| m.updated_at)
-                            .unwrap_or(0)
+                            .unwrap_or(0);
+                        let source = s.get_file_holders(cid)
+                            .unwrap_or_default()
+                            .into_iter()
+                            .next()
+                            .map(|(nid, _)| nid);
+                        (updated_at, source)
                     };
-                    match network.request_manifest_refresh(cid, upstream_nid, current_updated_at).await {
+                    let Some(upstream_nid) = refresh_source else { continue; };
+                    match network.request_manifest_refresh(cid, &upstream_nid, current_updated_at).await {
                         Ok(Some(cdn_manifest)) => {
                             if crypto::verify_manifest_signature(&cdn_manifest.author_manifest) {
                                 let author_json = serde_json::to_string(&cdn_manifest.author_manifest).unwrap_or_default();
@@ -3110,10 +3124,10 @@ impl Node {
                                     &cdn_manifest.author_manifest.author,
                                     cdn_manifest.author_manifest.updated_at,
                                 );
-                                // Relay to our downstream
-                                let downstream = s.get_blob_downstream(cid).unwrap_or_default();
+                                // Relay to known holders (flat set)
+                                let holders = s.get_file_holders(cid).unwrap_or_default();
                                 drop(s);
-                                if !downstream.is_empty() {
+                                if !holders.is_empty() {
                                     network.push_manifest_to_downstream(cid, &cdn_manifest).await;
                                 }
                                 tracing::debug!(
@@ -3126,7 +3140,7 @@ impl Node {
                         Err(e) => {
                             tracing::debug!(
                                 cid = hex::encode(cid),
-                                upstream = hex::encode(upstream_nid),
+                                upstream = hex::encode(&upstream_nid),
                                 error = %e,
                                 "Manifest refresh from upstream failed"
                             );
@@ -3277,18 +3291,16 @@ impl Node {
         compute_blob_priority_standalone(candidate, &self.node_id, follows, audience_members, now_ms)
     }
 
-    /// Delete a blob with CDN notifications to upstream/downstream.
+    /// Delete a blob with CDN notifications to known holders.
     pub async fn delete_blob_with_cdn_notify(&self, cid: &[u8; 32]) -> anyhow::Result<()> {
-        // Gather CDN peers before cleanup
-        let (downstream, upstream) = {
+        // Gather known holders before cleanup
+        let holders = {
             let storage = self.storage.get().await;
-            let ds = storage.get_blob_downstream(cid).unwrap_or_default();
-            let up = storage.get_blob_upstream(cid).ok().flatten();
-            (ds, up)
+            storage.get_file_holders(cid).unwrap_or_default()
         };
 
-        // Send CDN delete notices
-        self.network.send_blob_delete_notices(cid, &downstream, upstream.as_ref()).await;
+        // Send CDN delete notices to all holders
+        self.network.send_blob_delete_notices(cid, &holders, None).await;
 
         // Clean up local storage
         {
@@ -3576,15 +3588,9 @@ impl Node {
                 ops: vec![crate::types::BlobHeaderDiffOp::AddReaction(reaction.clone())],
                 timestamp_ms: now,
             };
+            // propagate_engagement_diff targets all file_holders (flat set, max 5)
+            // which already subsumes what used to be upstream + downstream.
             network.propagate_engagement_diff(&post_id, &diff, &our_node_id).await;
-            // Also send to all upstreams (toward author) — Phase 6 multi-upstream
-            let upstreams = {
-                let storage = self.storage.get().await;
-                storage.get_post_upstreams(&post_id).unwrap_or_default()
-            };
-            for (up, _prio) in upstreams {
-                let _ = network.send_to_peer_uni(&up, crate::protocol::MessageType::BlobHeaderDiff, &diff).await;
-            }
         }
 
         Ok(reaction)
@@ -3691,14 +3697,6 @@ impl Node {
                 timestamp_ms: now,
             };
             network.propagate_engagement_diff(&post_id, &diff, &our_node_id).await;
-            // Also send to all upstreams (toward author) — Phase 6 multi-upstream
-            let upstreams = {
-                let storage = self.storage.get().await;
-                storage.get_post_upstreams(&post_id).unwrap_or_default()
-            };
-            for (up, _prio) in upstreams {
-                let _ = network.send_to_peer_uni(&up, crate::protocol::MessageType::BlobHeaderDiff, &diff).await;
-            }
         }
 
         Ok(comment)
@@ -3735,14 +3733,6 @@ impl Node {
                 timestamp_ms: now,
             };
             network.propagate_engagement_diff(&post_id, &diff, &our_node_id).await;
-            // Phase 6: send to all upstreams
-            let upstreams = {
-                let storage = self.storage.get().await;
-                storage.get_post_upstreams(&post_id).unwrap_or_default()
-            };
-            for (up, _prio) in upstreams {
-                let _ = network.send_to_peer_uni(&up, crate::protocol::MessageType::BlobHeaderDiff, &diff).await;
-            }
         }
         Ok(())
     }
@@ -3776,14 +3766,6 @@ impl Node {
                 timestamp_ms: now,
             };
             network.propagate_engagement_diff(&post_id, &diff, &our_node_id).await;
-            // Phase 6: send to all upstreams
-            let upstreams = {
-                let storage = self.storage.get().await;
-                storage.get_post_upstreams(&post_id).unwrap_or_default()
-            };
-            for (up, _prio) in upstreams {
-                let _ = network.send_to_peer_uni(&up, crate::protocol::MessageType::BlobHeaderDiff, &diff).await;
-            }
         }
         Ok(())
     }
@@ -4005,14 +3987,6 @@ impl Node {
             timestamp_ms: now,
         };
         self.network.propagate_engagement_diff(&post_id, &diff, &self.node_id).await;
-        // Phase 6: send to all upstreams
-        let upstreams = {
-            let storage = self.storage.get().await;
-            storage.get_post_upstreams(&post_id).unwrap_or_default()
-        };
-        for (up, _prio) in upstreams {
-            let _ = self.network.send_to_peer_uni(&up, crate::protocol::MessageType::BlobHeaderDiff, &diff).await;
-        }
 
         Ok(())
     }
@@ -4127,14 +4101,6 @@ impl Node {
             timestamp_ms: now,
         };
         self.network.propagate_engagement_diff(&post_id, &diff, &self.node_id).await;
-        // Phase 6: send to all upstreams
-        let upstreams = {
-            let storage = self.storage.get().await;
-            storage.get_post_upstreams(&post_id).unwrap_or_default()
-        };
-        for (up, _prio) in upstreams {
-            let _ = self.network.send_to_peer_uni(&up, crate::protocol::MessageType::BlobHeaderDiff, &diff).await;
-        }
 
         Ok(())
     }
@@ -4367,10 +4333,10 @@ impl Node {
                 }
             };
 
-            // Filter to under-replicated (< 2 downstream)
+            // Filter to under-replicated (< 2 holders)
             let mut needs_replication = Vec::new();
             for pid in &recent_ids {
-                match storage.get_post_downstream_count(pid) {
+                match storage.get_file_holder_count(pid) {
                     Ok(count) if count < 2 => {
                         needs_replication.push(*pid);
                     }

crates/core/src/storage.rs

@@ -12,6 +12,26 @@ use crate::types::{
     VisibilityIntent,
 };
 
+/// Direction for file_holders entries: whether we sent the file to this peer,
+/// received it from them, or both. Not load-bearing for propagation decisions —
+/// any holder can serve as a diff target — but retained for potential reuse.
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum HolderDirection {
+    Sent,
+    Received,
+    Both,
+}
+
+impl HolderDirection {
+    pub fn as_str(&self) -> &'static str {
+        match self {
+            HolderDirection::Sent => "sent",
+            HolderDirection::Received => "received",
+            HolderDirection::Both => "both",
+        }
+    }
+}
+
 /// Blob metadata for eviction scoring.
 pub struct EvictionCandidate {
     pub cid: [u8; 32],
@@ -262,20 +282,6 @@ impl Storage {
                 updated_at INTEGER NOT NULL
             );
             CREATE INDEX IF NOT EXISTS idx_cdn_manifests_author ON cdn_manifests(author);
-            CREATE TABLE IF NOT EXISTS blob_upstream (
-                cid BLOB PRIMARY KEY,
-                source_node_id BLOB NOT NULL,
-                source_addresses TEXT NOT NULL DEFAULT '[]',
-                stored_at INTEGER NOT NULL
-            );
-            CREATE TABLE IF NOT EXISTS blob_downstream (
-                cid BLOB NOT NULL,
-                peer_node_id BLOB NOT NULL,
-                peer_addresses TEXT NOT NULL DEFAULT '[]',
-                registered_at INTEGER NOT NULL,
-                PRIMARY KEY (cid, peer_node_id)
-            );
-            CREATE INDEX IF NOT EXISTS idx_blob_downstream_cid ON blob_downstream(cid);
             CREATE TABLE IF NOT EXISTS group_keys (
                 group_id BLOB PRIMARY KEY,
                 circle_name TEXT NOT NULL,
@@ -326,17 +332,6 @@ impl Storage {
                 last_seen_ms INTEGER NOT NULL,
                 success_count INTEGER NOT NULL DEFAULT 0
             );
-            CREATE TABLE IF NOT EXISTS post_downstream (
-                post_id BLOB NOT NULL,
-                peer_node_id BLOB NOT NULL,
-                registered_at INTEGER NOT NULL,
-                PRIMARY KEY (post_id, peer_node_id)
-            );
-            CREATE INDEX IF NOT EXISTS idx_post_downstream_post ON post_downstream(post_id);
-            CREATE TABLE IF NOT EXISTS post_upstream (
-                post_id BLOB PRIMARY KEY,
-                peer_node_id BLOB NOT NULL
-            );
             CREATE TABLE IF NOT EXISTS blob_headers (
                 post_id BLOB PRIMARY KEY,
                 author BLOB NOT NULL,
@@ -389,7 +384,17 @@ impl Storage {
             CREATE TABLE IF NOT EXISTS seen_messages (
                 partner_id BLOB PRIMARY KEY,
                 last_read_ms INTEGER NOT NULL DEFAULT 0
-            );",
+            );
+            CREATE TABLE IF NOT EXISTS file_holders (
+                file_id BLOB NOT NULL,
+                peer_id BLOB NOT NULL,
+                peer_addresses TEXT NOT NULL DEFAULT '[]',
+                last_interaction_ms INTEGER NOT NULL,
+                direction TEXT NOT NULL,
+                PRIMARY KEY (file_id, peer_id)
+            );
+            CREATE INDEX IF NOT EXISTS idx_file_holders_recency
+                ON file_holders(file_id, last_interaction_ms DESC);",
         )?;
         Ok(())
     }
@@ -543,16 +548,6 @@ impl Storage {
             )?;
         }
 
-        // Add preferred_tree column to blob_upstream if missing (CDN Preferred Tree migration)
-        let has_blob_pref_tree = self.conn.prepare(
-            "SELECT COUNT(*) FROM pragma_table_info('blob_upstream') WHERE name='preferred_tree'"
-        )?.query_row([], |row| row.get::<_, i64>(0))?;
-        if has_blob_pref_tree == 0 {
-            self.conn.execute_batch(
-                "ALTER TABLE blob_upstream ADD COLUMN preferred_tree TEXT NOT NULL DEFAULT '[]';"
-            )?;
-        }
-
         // Add public_visible column to profiles if missing (Phase D-4 migration)
         let has_public_visible = self.conn.prepare(
             "SELECT COUNT(*) FROM pragma_table_info('profiles') WHERE name='public_visible'"
@@ -666,25 +661,18 @@ impl Storage {
             )?;
         }
 
-        // Protocol v4 Phase 6: Migrate post_upstream to multi-upstream (3 max)
-        let has_priority = self.conn.prepare(
-            "SELECT COUNT(*) FROM pragma_table_info('post_upstream') WHERE name='priority'"
-        )?.query_row([], |row| row.get::<_, i64>(0))?;
-        if has_priority == 0 {
-            self.conn.execute_batch(
-                "ALTER TABLE post_upstream RENAME TO post_upstream_old;
-                 CREATE TABLE post_upstream (
-                     post_id BLOB NOT NULL,
-                     peer_node_id BLOB NOT NULL,
-                     priority INTEGER NOT NULL DEFAULT 0,
-                     registered_at INTEGER NOT NULL DEFAULT 0,
-                     PRIMARY KEY (post_id, peer_node_id)
-                 );
-                 INSERT INTO post_upstream (post_id, peer_node_id, priority, registered_at)
-                     SELECT post_id, peer_node_id, 0, 0 FROM post_upstream_old;
-                 DROP TABLE post_upstream_old;"
-            )?;
-        }
+        // 0.6.1-beta: seed file_holders from legacy upstream/downstream tables
+        // before they're dropped. Idempotent — only fires on an empty
+        // file_holders table.
+        self.seed_file_holders_from_legacy()?;
+
+        // 0.6.1-beta: drop legacy directional tables — replaced by file_holders.
+        self.conn.execute_batch(
+            "DROP TABLE IF EXISTS blob_upstream;
+             DROP TABLE IF EXISTS blob_downstream;
+             DROP TABLE IF EXISTS post_upstream;
+             DROP TABLE IF EXISTS post_downstream;",
+        )?;
 
         Ok(())
     }
@@ -2396,8 +2384,7 @@ impl Storage {
             params![record.post_id.as_slice(), record.author.as_slice()],
         )?;
         if deleted > 0 {
-            self.conn.execute("DELETE FROM post_downstream WHERE post_id = ?1", params![record.post_id.as_slice()])?;
-            self.conn.execute("DELETE FROM post_upstream WHERE post_id = ?1", params![record.post_id.as_slice()])?;
+            self.conn.execute("DELETE FROM file_holders WHERE file_id = ?1", params![record.post_id.as_slice()])?;
             self.conn.execute("DELETE FROM seen_engagement WHERE post_id = ?1", params![record.post_id.as_slice()])?;
         }
         Ok(deleted > 0)
@@ -3396,28 +3383,6 @@ impl Storage {
         Ok(())
     }
 
-    /// Update the preferred_tree JSON for a blob upstream entry.
-    pub fn update_blob_upstream_preferred_tree(&self, cid: &[u8; 32], tree: &[NodeId]) -> anyhow::Result<()> {
-        let json = serde_json::to_string(
-            &tree.iter().map(hex::encode).collect::<Vec<_>>()
-        )?;
-        self.conn.execute(
-            "UPDATE blob_upstream SET preferred_tree = ?1 WHERE cid = ?2",
-            params![json, cid.as_slice()],
-        )?;
-        Ok(())
-    }
-
-    /// Get the preferred_tree for a blob upstream entry.
-    pub fn get_blob_upstream_preferred_tree(&self, cid: &[u8; 32]) -> anyhow::Result<Vec<NodeId>> {
-        let json: String = self.conn.query_row(
-            "SELECT preferred_tree FROM blob_upstream WHERE cid = ?1",
-            params![cid.as_slice()],
-            |row| row.get(0),
-        ).unwrap_or_else(|_| "[]".to_string());
-        Ok(parse_anchors_json(&json))
-    }
-
     // ---- Social Routes ----
 
     /// Insert or update a social route entry.
@@ -3889,10 +3854,10 @@ impl Storage {
                  GROUP BY post_id
              ) r ON b.post_id = r.post_id
              LEFT JOIN (
-                 SELECT cid, COUNT(*) as ds_count
-                 FROM blob_downstream
-                 GROUP BY cid
-             ) d ON b.cid = d.cid"
+                 SELECT file_id, COUNT(*) as ds_count
+                 FROM file_holders
+                 GROUP BY file_id
+             ) d ON b.cid = d.file_id"
         )?;
         let rows = stmt.query_map(params![cutoff], |row| {
             let cid_bytes: Vec<u8> = row.get(0)?;
@@ -3946,11 +3911,10 @@ impl Storage {
         Ok(count as u64)
     }
 
-    /// Clean up all CDN metadata for a blob (manifests + upstream + downstream).
+    /// Clean up all CDN metadata for a blob (manifests + file_holders).
     pub fn cleanup_cdn_for_blob(&self, cid: &[u8; 32]) -> anyhow::Result<()> {
         self.conn.execute("DELETE FROM cdn_manifests WHERE cid = ?1", params![cid.as_slice()])?;
-        self.conn.execute("DELETE FROM blob_upstream WHERE cid = ?1", params![cid.as_slice()])?;
-        self.conn.execute("DELETE FROM blob_downstream WHERE cid = ?1", params![cid.as_slice()])?;
+        self.conn.execute("DELETE FROM file_holders WHERE file_id = ?1", params![cid.as_slice()])?;
         Ok(())
     }
 
@@ -3969,12 +3933,6 @@ impl Storage {
         Ok(cids)
     }
 
-    /// Remove upstream tracking for a blob CID.
-    pub fn remove_blob_upstream(&self, cid: &[u8; 32]) -> anyhow::Result<()> {
-        self.conn.execute("DELETE FROM blob_upstream WHERE cid = ?1", params![cid.as_slice()])?;
-        Ok(())
-    }
-
     pub fn post_count(&self) -> anyhow::Result<usize> {
         let count: i64 = self
             .conn
@@ -4037,137 +3995,24 @@ impl Storage {
         Ok(result)
     }
 
-    /// Record the upstream source for a blob CID.
-    pub fn store_blob_upstream(
-        &self,
-        cid: &[u8; 32],
-        source_node_id: &NodeId,
-        source_addresses: &[String],
-    ) -> anyhow::Result<()> {
-        let addrs_json = serde_json::to_string(source_addresses)?;
-        self.conn.execute(
-            "INSERT INTO blob_upstream (cid, source_node_id, source_addresses, stored_at) VALUES (?1, ?2, ?3, ?4)
-             ON CONFLICT(cid) DO UPDATE SET source_node_id = ?2, source_addresses = ?3, stored_at = ?4",
-            params![cid.as_slice(), source_node_id.as_slice(), addrs_json, now_ms()],
-        )?;
-        Ok(())
-    }
-
-    /// Get the upstream source for a blob CID: (node_id, addresses).
-    pub fn get_blob_upstream(&self, cid: &[u8; 32]) -> anyhow::Result<Option<(NodeId, Vec<String>)>> {
-        let result = self.conn.query_row(
-            "SELECT source_node_id, source_addresses FROM blob_upstream WHERE cid = ?1",
-            params![cid.as_slice()],
-            |row| {
-                let nid_bytes: Vec<u8> = row.get(0)?;
-                let addrs_json: String = row.get(1)?;
-                Ok((nid_bytes, addrs_json))
-            },
-        );
-        match result {
-            Ok((nid_bytes, addrs_json)) => {
-                let nid = blob_to_nodeid(nid_bytes)?;
-                let addrs: Vec<String> = serde_json::from_str(&addrs_json).unwrap_or_default();
-                Ok(Some((nid, addrs)))
-            }
-            Err(rusqlite::Error::QueryReturnedNoRows) => Ok(None),
-            Err(e) => Err(e.into()),
-        }
-    }
-
-    /// Register a downstream peer for a blob CID. Returns false if already at 100 downstream.
-    pub fn add_blob_downstream(
-        &self,
-        cid: &[u8; 32],
-        peer_node_id: &NodeId,
-        peer_addresses: &[String],
-    ) -> anyhow::Result<bool> {
-        let count = self.get_blob_downstream_count(cid)?;
-        if count >= 100 {
-            return Ok(false);
-        }
-        let addrs_json = serde_json::to_string(peer_addresses)?;
-        self.conn.execute(
-            "INSERT INTO blob_downstream (cid, peer_node_id, peer_addresses, registered_at) VALUES (?1, ?2, ?3, ?4)
-             ON CONFLICT(cid, peer_node_id) DO UPDATE SET peer_addresses = ?3, registered_at = ?4",
-            params![cid.as_slice(), peer_node_id.as_slice(), addrs_json, now_ms()],
-        )?;
-        Ok(true)
-    }
-
-    /// Get all downstream peers for a blob CID: Vec<(node_id, addresses)>.
-    pub fn get_blob_downstream(&self, cid: &[u8; 32]) -> anyhow::Result<Vec<(NodeId, Vec<String>)>> {
+    /// Get CIDs of manifests older than a cutoff. Callers look up holders
+    /// via file_holders to pick a refresh source.
+    pub fn get_stale_manifest_cids(&self, older_than_ms: u64) -> anyhow::Result<Vec<[u8; 32]>> {
         let mut stmt = self.conn.prepare(
-            "SELECT peer_node_id, peer_addresses FROM blob_downstream WHERE cid = ?1"
-        )?;
-        let rows = stmt.query_map(params![cid.as_slice()], |row| {
-            let nid_bytes: Vec<u8> = row.get(0)?;
-            let addrs_json: String = row.get(1)?;
-            Ok((nid_bytes, addrs_json))
-        })?;
-        let mut result = Vec::new();
-        for row in rows {
-            let (nid_bytes, addrs_json) = row?;
-            let nid = blob_to_nodeid(nid_bytes)?;
-            let addrs: Vec<String> = serde_json::from_str(&addrs_json).unwrap_or_default();
-            result.push((nid, addrs));
-        }
-        Ok(result)
-    }
-
-    /// Count downstream peers for a blob CID.
-    pub fn get_blob_downstream_count(&self, cid: &[u8; 32]) -> anyhow::Result<u32> {
-        let count: i64 = self.conn.query_row(
-            "SELECT COUNT(*) FROM blob_downstream WHERE cid = ?1",
-            params![cid.as_slice()],
-            |row| row.get(0),
-        )?;
-        Ok(count as u32)
-    }
-
-    /// Remove a downstream peer for a blob CID.
-    pub fn remove_blob_downstream(&self, cid: &[u8; 32], peer_node_id: &NodeId) -> anyhow::Result<()> {
-        self.conn.execute(
-            "DELETE FROM blob_downstream WHERE cid = ?1 AND peer_node_id = ?2",
-            params![cid.as_slice(), peer_node_id.as_slice()],
-        )?;
-        Ok(())
-    }
-
-    /// Get manifests older than a cutoff: Vec<(cid, upstream_node_id, upstream_addresses)>.
-    pub fn get_stale_manifests(&self, older_than_ms: u64) -> anyhow::Result<Vec<([u8; 32], NodeId, Vec<String>)>> {
-        let mut stmt = self.conn.prepare(
-            "SELECT m.cid, u.source_node_id, u.source_addresses
-             FROM cdn_manifests m
-             LEFT JOIN blob_upstream u ON m.cid = u.cid
-             WHERE m.updated_at < ?1"
+            "SELECT cid FROM cdn_manifests WHERE updated_at < ?1",
         )?;
         let rows = stmt.query_map(params![older_than_ms as i64], |row| {
             let cid_bytes: Vec<u8> = row.get(0)?;
-            let nid_bytes: Option<Vec<u8>> = row.get(1)?;
-            let addrs_json: Option<String> = row.get(2)?;
-            Ok((cid_bytes, nid_bytes, addrs_json))
+            Ok(cid_bytes)
         })?;
-        let mut result = Vec::new();
+        let mut out = Vec::new();
         for row in rows {
-            let (cid_bytes, nid_bytes, addrs_json) = row?;
-            let cid: [u8; 32] = match cid_bytes.try_into() {
-                Ok(c) => c,
-                Err(_) => continue,
-            };
-            let nid = match nid_bytes {
-                Some(b) => match blob_to_nodeid(b) {
-                    Ok(n) => n,
-                    Err(_) => continue,
-                },
-                None => continue,
-            };
-            let addrs: Vec<String> = addrs_json
-                .map(|j| serde_json::from_str(&j).unwrap_or_default())
-                .unwrap_or_default();
-            result.push((cid, nid, addrs));
+            let cid_bytes = row?;
+            if let Ok(cid) = <[u8; 32]>::try_from(cid_bytes.as_slice()) {
+                out.push(cid);
+            }
         }
-        Ok(result)
+        Ok(out)
     }
 
     /// Get the 10 posts before and 10 posts after a reference timestamp for an author.
@@ -4271,128 +4116,148 @@ impl Storage {
         Ok(result)
     }
 
-    // --- Engagement: post_downstream ---
+    // --- File holders (flat, per-file, LRU-capped at 5) ---
+    //
+    // A single table for PostId-keyed engagement propagation and CID-keyed
+    // manifest/blob propagation. Any 32-byte content-addressed file_id fits.
 
-    /// Register a peer as downstream for a post (max 100 per post).
-    /// Returns true if added, false if at capacity.
-    pub fn add_post_downstream(&self, post_id: &PostId, peer_node_id: &NodeId) -> anyhow::Result<bool> {
-        let count: i64 = self.conn.prepare(
-            "SELECT COUNT(*) FROM post_downstream WHERE post_id = ?1"
-        )?.query_row(params![post_id.as_slice()], |row| row.get(0))?;
-        if count >= 100 {
-            return Ok(false);
-        }
-        self.conn.execute(
-            "INSERT INTO post_downstream (post_id, peer_node_id, registered_at) VALUES (?1, ?2, ?3)
-             ON CONFLICT DO NOTHING",
-            params![post_id.as_slice(), peer_node_id.as_slice(), now_ms()],
-        )?;
-        Ok(true)
-    }
-
-    /// Get all downstream peers for a post.
-    pub fn get_post_downstream(&self, post_id: &PostId) -> anyhow::Result<Vec<NodeId>> {
-        let mut stmt = self.conn.prepare(
-            "SELECT peer_node_id FROM post_downstream WHERE post_id = ?1"
-        )?;
-        let rows = stmt.query_map(params![post_id.as_slice()], |row| row.get::<_, Vec<u8>>(0))?;
-        let mut result = Vec::new();
-        for row in rows {
-            if let Ok(nid) = blob_to_nodeid(row?) {
-                result.push(nid);
-            }
-        }
-        Ok(result)
-    }
-
-    /// Remove a downstream peer for a post.
-    pub fn remove_post_downstream(&self, post_id: &PostId, peer_node_id: &NodeId) -> anyhow::Result<()> {
-        self.conn.execute(
-            "DELETE FROM post_downstream WHERE post_id = ?1 AND peer_node_id = ?2",
-            params![post_id.as_slice(), peer_node_id.as_slice()],
-        )?;
-        Ok(())
-    }
-
-    // --- Engagement: post_upstream (multi-upstream, 3 max) ---
-
-    /// Add an upstream peer for a post. INSERT OR IGNORE, cap at 3 per post.
-    pub fn add_post_upstream(&self, post_id: &PostId, peer_node_id: &NodeId, priority: u8) -> anyhow::Result<()> {
-        // Check current count
-        let count: i64 = self.conn.prepare(
-            "SELECT COUNT(*) FROM post_upstream WHERE post_id = ?1"
-        )?.query_row(params![post_id.as_slice()], |row| row.get(0))?;
-        if count >= 3 {
-            return Ok(()); // Already at cap
-        }
+    /// Upsert a holder for a file. Bumps last_interaction_ms to now and
+    /// enforces an LRU cap of 5 holders per file.
+    pub fn touch_file_holder(
+        &self,
+        file_id: &[u8; 32],
+        peer_id: &NodeId,
+        peer_addresses: &[String],
+        direction: HolderDirection,
+    ) -> anyhow::Result<()> {
+        let addrs_json = serde_json::to_string(peer_addresses)?;
         let now = now_ms();
+        let new_dir = direction.as_str();
+        // Upsert. If the row exists with a different direction, promote to "both".
         self.conn.execute(
-            "INSERT OR IGNORE INTO post_upstream (post_id, peer_node_id, priority, registered_at)
-             VALUES (?1, ?2, ?3, ?4)",
-            params![post_id.as_slice(), peer_node_id.as_slice(), priority as i64, now],
+            "INSERT INTO file_holders (file_id, peer_id, peer_addresses, last_interaction_ms, direction)
+             VALUES (?1, ?2, ?3, ?4, ?5)
+             ON CONFLICT(file_id, peer_id) DO UPDATE SET
+                peer_addresses = CASE WHEN length(?3) > 2 THEN ?3 ELSE peer_addresses END,
+                last_interaction_ms = ?4,
+                direction = CASE WHEN direction = ?5 THEN direction ELSE 'both' END",
+            params![file_id.as_slice(), peer_id.as_slice(), addrs_json, now as i64, new_dir],
+        )?;
+        // Enforce LRU cap of 5. Oldest get dropped.
+        self.conn.execute(
+            "DELETE FROM file_holders
+             WHERE file_id = ?1
+               AND peer_id NOT IN (
+                   SELECT peer_id FROM file_holders
+                   WHERE file_id = ?1
+                   ORDER BY last_interaction_ms DESC
+                   LIMIT 5
+               )",
+            params![file_id.as_slice()],
         )?;
         Ok(())
     }
 
-    /// Get all upstream peers for a post, ordered by priority ASC (0 = primary).
-    pub fn get_post_upstreams(&self, post_id: &PostId) -> anyhow::Result<Vec<(NodeId, u8)>> {
-        let mut stmt = self.conn.prepare(
-            "SELECT peer_node_id, priority FROM post_upstream WHERE post_id = ?1 ORDER BY priority ASC"
-        )?;
-        let rows = stmt.query_map(params![post_id.as_slice()], |row| {
-            let bytes: Vec<u8> = row.get(0)?;
-            let prio: i64 = row.get(1)?;
-            Ok((bytes, prio as u8))
-        })?;
-        let mut result = Vec::new();
-        for row in rows {
-            let (bytes, prio) = row?;
-            if let Ok(nid) = <[u8; 32]>::try_from(bytes.as_slice()) {
-                result.push((nid, prio));
-            }
-        }
-        Ok(result)
-    }
-
-    /// Get the primary (lowest priority) upstream peer for a post.
-    /// Backward-compatible wrapper for code that only needs a single upstream.
-    pub fn get_post_upstream(&self, post_id: &PostId) -> anyhow::Result<Option<NodeId>> {
-        let upstreams = self.get_post_upstreams(post_id)?;
-        Ok(upstreams.into_iter().next().map(|(nid, _)| nid))
-    }
-
-    /// Remove a specific upstream peer for a post.
-    pub fn remove_post_upstream(&self, post_id: &PostId, peer_node_id: &NodeId) -> anyhow::Result<()> {
-        self.conn.execute(
-            "DELETE FROM post_upstream WHERE post_id = ?1 AND peer_node_id = ?2",
-            params![post_id.as_slice(), peer_node_id.as_slice()],
-        )?;
-        Ok(())
-    }
-
-    /// Promote an upstream peer to primary (priority 0), pushing others up.
-    pub fn promote_post_upstream(&self, post_id: &PostId, peer_node_id: &NodeId) -> anyhow::Result<()> {
-        // Shift all priorities up by 1
-        self.conn.execute(
-            "UPDATE post_upstream SET priority = priority + 1 WHERE post_id = ?1",
-            params![post_id.as_slice()],
-        )?;
-        // Set the promoted peer to priority 0
-        self.conn.execute(
-            "UPDATE post_upstream SET priority = 0 WHERE post_id = ?1 AND peer_node_id = ?2",
-            params![post_id.as_slice(), peer_node_id.as_slice()],
-        )?;
-        Ok(())
-    }
-
-    /// Count downstream peers for a post.
-    pub fn get_post_downstream_count(&self, post_id: &PostId) -> anyhow::Result<u32> {
+    /// Count file holders (bounded at 5 by touch_file_holder's LRU cap).
+    pub fn get_file_holder_count(&self, file_id: &[u8; 32]) -> anyhow::Result<u32> {
         let count: i64 = self.conn.prepare(
-            "SELECT COUNT(*) FROM post_downstream WHERE post_id = ?1"
-        )?.query_row(params![post_id.as_slice()], |row| row.get(0))?;
+            "SELECT COUNT(*) FROM file_holders WHERE file_id = ?1",
+        )?.query_row(params![file_id.as_slice()], |row| row.get(0))?;
         Ok(count as u32)
     }
 
+    /// Return the up-to-5 most recently interacted holders of a file.
+    pub fn get_file_holders(&self, file_id: &[u8; 32]) -> anyhow::Result<Vec<(NodeId, Vec<String>)>> {
+        let mut stmt = self.conn.prepare(
+            "SELECT peer_id, peer_addresses FROM file_holders
+             WHERE file_id = ?1
+             ORDER BY last_interaction_ms DESC
+             LIMIT 5",
+        )?;
+        let rows = stmt.query_map(params![file_id.as_slice()], |row| {
+            let peer_bytes: Vec<u8> = row.get(0)?;
+            let addrs_json: String = row.get(1)?;
+            Ok((peer_bytes, addrs_json))
+        })?;
+        let mut out = Vec::new();
+        for row in rows {
+            let (peer_bytes, addrs_json) = row?;
+            if peer_bytes.len() != 32 { continue; }
+            let mut peer = [0u8; 32];
+            peer.copy_from_slice(&peer_bytes);
+            let addrs: Vec<String> = serde_json::from_str(&addrs_json).unwrap_or_default();
+            out.push((NodeId::from(peer), addrs));
+        }
+        Ok(out)
+    }
+
+    /// Remove all holders for a file (e.g. on post/blob deletion).
+    pub fn delete_file_holders(&self, file_id: &[u8; 32]) -> anyhow::Result<()> {
+        self.conn.execute(
+            "DELETE FROM file_holders WHERE file_id = ?1",
+            params![file_id.as_slice()],
+        )?;
+        Ok(())
+    }
+
+    /// Remove a single peer's holder entry for a file.
+    pub fn remove_file_holder(&self, file_id: &[u8; 32], peer_id: &NodeId) -> anyhow::Result<()> {
+        self.conn.execute(
+            "DELETE FROM file_holders WHERE file_id = ?1 AND peer_id = ?2",
+            params![file_id.as_slice(), peer_id.as_slice()],
+        )?;
+        Ok(())
+    }
+
+    /// One-time migration: seed file_holders from the legacy upstream/downstream
+    /// tables so a user upgrading from pre-0.6.1 doesn't start with empty holder
+    /// sets. Idempotent — inserts use ON CONFLICT DO NOTHING semantics via the
+    /// PRIMARY KEY. Skips tables that don't exist on fresh installs.
+    pub fn seed_file_holders_from_legacy(&self) -> anyhow::Result<()> {
+        // Skip if file_holders already populated (idempotent re-run protection).
+        let existing: i64 = self.conn.prepare("SELECT COUNT(*) FROM file_holders")?
+            .query_row([], |row| row.get(0))?;
+        if existing > 0 {
+            return Ok(());
+        }
+        let now = now_ms() as i64;
+        let table_exists = |name: &str| -> anyhow::Result<bool> {
+            let count: i64 = self.conn.prepare(
+                "SELECT COUNT(*) FROM sqlite_master WHERE type='table' AND name=?1",
+            )?.query_row(params![name], |row| row.get(0))?;
+            Ok(count > 0)
+        };
+        if table_exists("post_upstream")? {
+            self.conn.execute(
+                "INSERT OR IGNORE INTO file_holders (file_id, peer_id, peer_addresses, last_interaction_ms, direction)
+                 SELECT post_id, peer_node_id, '[]', ?1, 'received' FROM post_upstream",
+                params![now],
+            )?;
+        }
+        if table_exists("post_downstream")? {
+            self.conn.execute(
+                "INSERT OR IGNORE INTO file_holders (file_id, peer_id, peer_addresses, last_interaction_ms, direction)
+                 SELECT post_id, peer_node_id, '[]', ?1, 'sent' FROM post_downstream",
+                params![now],
+            )?;
+        }
+        if table_exists("blob_upstream")? {
+            self.conn.execute(
+                "INSERT OR IGNORE INTO file_holders (file_id, peer_id, peer_addresses, last_interaction_ms, direction)
+                 SELECT cid, source_node_id, source_addresses, ?1, 'received' FROM blob_upstream",
+                params![now],
+            )?;
+        }
+        if table_exists("blob_downstream")? {
+            self.conn.execute(
+                "INSERT OR IGNORE INTO file_holders (file_id, peer_id, peer_addresses, last_interaction_ms, direction)
+                 SELECT cid, peer_node_id, peer_addresses, ?1, 'sent' FROM blob_downstream",
+                params![now],
+            )?;
+        }
+        Ok(())
+    }
+
     // --- Engagement: reactions ---
 
     /// Store a reaction (upsert by reactor+post_id+emoji).
@@ -5301,60 +5166,6 @@ mod tests {
         assert_eq!(manifests[0].0, cid);
     }
 
-    #[test]
-    fn blob_upstream_crud() {
-        let s = temp_storage();
-        let cid = [42u8; 32];
-        let source = make_node_id(1);
-        let addrs = vec!["10.0.0.1:4433".to_string()];
-
-        s.store_blob_upstream(&cid, &source, &addrs).unwrap();
-        let (nid, got_addrs) = s.get_blob_upstream(&cid).unwrap().unwrap();
-        assert_eq!(nid, source);
-        assert_eq!(got_addrs, addrs);
-
-        // Missing
-        assert!(s.get_blob_upstream(&[99u8; 32]).unwrap().is_none());
-
-        // Update
-        let source2 = make_node_id(2);
-        s.store_blob_upstream(&cid, &source2, &[]).unwrap();
-        let (nid, _) = s.get_blob_upstream(&cid).unwrap().unwrap();
-        assert_eq!(nid, source2);
-    }
-
-    #[test]
-    fn blob_downstream_crud_and_limit() {
-        let s = temp_storage();
-        let cid = [42u8; 32];
-
-        // Add downstream peers
-        for i in 0..100u8 {
-            let peer = make_node_id(i);
-            let ok = s.add_blob_downstream(&cid, &peer, &[format!("10.0.0.{}:4433", i)]).unwrap();
-            assert!(ok, "should accept peer {}", i);
-        }
-
-        assert_eq!(s.get_blob_downstream_count(&cid).unwrap(), 100);
-
-        // 101st should be rejected
-        let peer_101 = make_node_id(200);
-        let ok = s.add_blob_downstream(&cid, &peer_101, &[]).unwrap();
-        assert!(!ok, "should reject 101st downstream");
-
-        // Get all downstream
-        let downstream = s.get_blob_downstream(&cid).unwrap();
-        assert_eq!(downstream.len(), 100);
-
-        // Remove one
-        s.remove_blob_downstream(&cid, &make_node_id(0)).unwrap();
-        assert_eq!(s.get_blob_downstream_count(&cid).unwrap(), 99);
-
-        // Now adding one more should work
-        let ok = s.add_blob_downstream(&cid, &peer_101, &[]).unwrap();
-        assert!(ok, "should accept after removal");
-    }
-
     #[test]
     fn blob_pin_unpin() {
         let s = temp_storage();
@@ -5438,18 +5249,15 @@ mod tests {
         let peer = make_node_id(2);
 
         s.store_cdn_manifest(&cid, r#"{"test": true}"#, &author, 100).unwrap();
-        s.store_blob_upstream(&cid, &peer, &["10.0.0.1:4433".to_string()]).unwrap();
-        s.add_blob_downstream(&cid, &peer, &["10.0.0.2:4433".to_string()]).unwrap();
+        s.touch_file_holder(&cid, &peer, &["10.0.0.1:4433".to_string()], HolderDirection::Received).unwrap();
 
         assert!(s.get_cdn_manifest(&cid).unwrap().is_some());
-        assert!(s.get_blob_upstream(&cid).unwrap().is_some());
-        assert_eq!(s.get_blob_downstream_count(&cid).unwrap(), 1);
+        assert_eq!(s.get_file_holder_count(&cid).unwrap(), 1);
 
         s.cleanup_cdn_for_blob(&cid).unwrap();
 
         assert!(s.get_cdn_manifest(&cid).unwrap().is_none());
-        assert!(s.get_blob_upstream(&cid).unwrap().is_none());
-        assert_eq!(s.get_blob_downstream_count(&cid).unwrap(), 0);
+        assert_eq!(s.get_file_holder_count(&cid).unwrap(), 0);
     }
 
     #[test]
@@ -5469,18 +5277,6 @@ mod tests {
         assert!(cids.contains(&cid2));
     }
 
-    #[test]
-    fn remove_blob_upstream() {
-        let s = temp_storage();
-        let cid = [42u8; 32];
-        let peer = make_node_id(1);
-
-        s.store_blob_upstream(&cid, &peer, &["10.0.0.1:4433".to_string()]).unwrap();
-        assert!(s.get_blob_upstream(&cid).unwrap().is_some());
-
-        s.remove_blob_upstream(&cid).unwrap();
-        assert!(s.get_blob_upstream(&cid).unwrap().is_none());
-    }
 
     #[test]
     fn author_post_neighborhood() {
@@ -5840,24 +5636,6 @@ mod tests {
         assert_eq!(got2.preferred_tree.len(), 2);
     }
 
-    #[test]
-    fn blob_upstream_preferred_tree() {
-        let s = temp_storage();
-        let cid = [42u8; 32];
-        let source = make_node_id(1);
-        s.store_blob_upstream(&cid, &source, &[]).unwrap();
-
-        // Initially empty
-        let tree = s.get_blob_upstream_preferred_tree(&cid).unwrap();
-        assert!(tree.is_empty());
-
-        // Update
-        let nodes = vec![make_node_id(10), make_node_id(11)];
-        s.update_blob_upstream_preferred_tree(&cid, &nodes).unwrap();
-        let tree2 = s.get_blob_upstream_preferred_tree(&cid).unwrap();
-        assert_eq!(tree2.len(), 2);
-    }
-
     // ---- Circle Profile tests ----
 
     #[test]
@@ -6058,32 +5836,39 @@ mod tests {
     // --- Engagement tests ---
 
     #[test]
-    fn post_downstream_crud() {
+    fn file_holders_lru_cap() {
         let s = temp_storage();
-        let post_id = make_post_id(1);
-        let peer1 = make_node_id(1);
-        let peer2 = make_node_id(2);
-
-        // Add downstream peers
-        assert!(s.add_post_downstream(&post_id, &peer1).unwrap());
-        assert!(s.add_post_downstream(&post_id, &peer2).unwrap());
-
-        let downstream = s.get_post_downstream(&post_id).unwrap();
-        assert_eq!(downstream.len(), 2);
-        assert_eq!(s.get_post_downstream_count(&post_id).unwrap(), 2);
-
-        // Remove one
-        s.remove_post_downstream(&post_id, &peer1).unwrap();
-        assert_eq!(s.get_post_downstream_count(&post_id).unwrap(), 1);
-
-        // Capacity limit
-        let big_post = make_post_id(99);
-        for i in 0..100u8 {
-            assert!(s.add_post_downstream(&big_post, &make_node_id(i + 1)).unwrap());
+        let file = [42u8; 32];
+        // Sleep between inserts so last_interaction_ms actually differs (ms resolution).
+        for i in 0..7u8 {
+            s.touch_file_holder(&file, &make_node_id(i), &[], HolderDirection::Received).unwrap();
+            std::thread::sleep(std::time::Duration::from_millis(2));
         }
-        assert_eq!(s.get_post_downstream_count(&big_post).unwrap(), 100);
-        // 101st should fail
-        assert!(!s.add_post_downstream(&big_post, &make_node_id(200)).unwrap());
+        // Only 5 most-recent survive
+        assert_eq!(s.get_file_holder_count(&file).unwrap(), 5);
+        let holders = s.get_file_holders(&file).unwrap();
+        assert_eq!(holders.len(), 5);
+        let kept: std::collections::HashSet<_> = holders.iter().map(|(n, _)| *n).collect();
+        // Oldest two (i=0, i=1) got evicted; most recent (i=6) survives
+        assert!(!kept.contains(&make_node_id(0)));
+        assert!(!kept.contains(&make_node_id(1)));
+        assert!(kept.contains(&make_node_id(6)));
+    }
+
+    #[test]
+    fn file_holders_direction_promotion() {
+        let s = temp_storage();
+        let file = [42u8; 32];
+        let peer = make_node_id(1);
+        s.touch_file_holder(&file, &peer, &[], HolderDirection::Received).unwrap();
+        s.touch_file_holder(&file, &peer, &[], HolderDirection::Sent).unwrap();
+        // Re-insert with opposite direction should promote to "both"
+        let dir: String = s.conn.query_row(
+            "SELECT direction FROM file_holders WHERE file_id = ?1 AND peer_id = ?2",
+            rusqlite::params![file.as_slice(), peer.as_slice()],
+            |row| row.get(0),
+        ).unwrap();
+        assert_eq!(dir, "both");
     }
 
     #[test]

crates/core/src/web.rs

@@ -132,8 +132,8 @@ async fn serve_post(stream: &mut TcpStream, path: &str, node: &Arc<Node>, browse
         if let Some(author) = author_id {
             holders.push(author);
         }
-        if let Ok(downstream) = store.get_post_downstream(&post_id) {
-            for peer in downstream {
+        if let Ok(file_holders) = store.get_file_holders(&post_id) {
+            for (peer, _addrs) in file_holders {
                 if !holders.contains(&peer) {
                     holders.push(peer);
                 }