People tab rewrite: recency sort, profile-post Discover, bio modal,

per-author feed filter, ignore primitive

The old People tab was built on network-layer presence (`is_online`,
`last_seen` from the mesh), which was lost when v0.6.1 anonymized the
network id from the posting id. Every named follow is authored under a
posting id that doesn't appear in the connection-layer tables; the
"Online" section listed nobody useful and Discover depended on the
same broken signal.

Replaced with signals derived from signed content:
- Following is sorted by most-recent-post timestamp (the real meaning
  of "activity" in a post-anonymization world).
- Discover lists named peers we've received signed profile posts from
  (via Phase 2d), filtered by follows / ignores / self.
- Click-a-name surfaces a bio modal with View Posts / Follow / Message
  / Ignore actions.
- Author-scoped feed filter (`View Posts` on any person) renders a
  "Showing posts from X" banner with a Clear button.
- Ignore is a new local-only primitive; ignored peers' posts and
  profiles are excluded everywhere and the ignored list is editable
  in Settings.

Core changes:

- New `ignored_peers(node_id, ignored_at)` table + storage helpers
  (`add_ignored_peer`, `remove_ignored_peer`, `list_ignored_peers`,
  `is_ignored_peer`). Schema created fresh; no migration since the
  table is purely additive and empty on prior installs.
- All 6 feed-query sites now also exclude `author IN ignored_peers`.
- New `Storage::last_activity_for_authors(&[NodeId])` — one batched
  query returning max post timestamp per author, excluding non-feed
  intents (Control / Profile / Announcement / GroupKeyDistribute).
- New `Storage::list_discoverable_profiles(&self_id)` — named profile
  rows where node_id is not self, not in follows, not in ignored, and
  `public_visible = 1`. Sorted by profile `updated_at` DESC.
- New `Storage::delete_setting(key)` — missing counterpart to
  set/get.
- Node wrappers: `last_activity_for_follows`, `ignore_peer`
  (also drops any follow + social route for the ignored peer),
  `unignore_peer`, `list_ignored_peers`, `list_discoverable_profiles`.
- `list_follows` Tauri command now sources `last_activity_ms` from
  the posts-driven batched query rather than the network peer record.

Tauri commands: `list_discover`, `ignore_peer`, `unignore_peer`,
`list_ignored_peers`.

Frontend:
- Following list: see-new-activity button pattern (staged data +
  explicit user click to rearrange, so the list doesn't reorder under
  a tap mid-scroll). Periodic people-tab polling stages + lights up
  the button; clicking it re-renders.
- Discover: rewrites the old peer-table-based list to a profile-post
  feed. Each card shows name + bio + profile-update age, plus Follow
  / Posts / Ignore actions.
- Bio modal: reuses the existing generic popover. Loads display name
  + bio via `resolve_display`, shows follow state, offers View Posts /
  Follow-or-Unfollow / Message / Ignore-or-Unignore.
- Author filter: banner renders at the top of the feed when active;
  clear button restores full feed. Filter state is a single `authorFilterNodeId`
  field consumed by `filterFeedPosts`.
- Settings → Ignored section lists ignored peers with unignore buttons.

124 / 124 core tests pass.

frontend/index.html

@@ -127,14 +127,18 @@
     <!-- People tab -->
     <section id="view-people" class="view">
       <div class="section-card">
-        <h3>Following</h3>
+        <div style="display:flex;align-items:center;justify-content:space-between;gap:0.5rem;margin-bottom:0.4rem">
+          <h3 style="margin:0">Following</h3>
+          <button id="follows-refresh-btn" class="btn btn-ghost btn-sm hidden" style="background:#1f3f38;color:#7fdbca;border:1px solid #7fdbca">See new activity</button>
+        </div>
+        <p class="empty-hint" style="margin:0 0 0.5rem;font-size:0.75rem">Sorted by last post. Tap a name to see their bio.</p>
         <div id="follows-list"></div>
       </div>
 
       <div class="section-card">
         <button id="discover-toggle" class="btn btn-ghost btn-sm section-toggle">Discover People</button>
         <div id="discover-body" class="hidden">
-          <p class="empty-hint" style="margin-bottom:0.5rem">People on the network with profiles you can follow.</p>
+          <p class="empty-hint" style="margin-bottom:0.5rem">Named profiles on the network you haven't followed or ignored.</p>
           <div id="discover-list"></div>
         </div>
       </div>
@@ -188,6 +192,12 @@
         <div id="circle-profiles-body" class="hidden"><div id="circle-profiles-list"></div></div>
       </div>
 
+      <div class="section-card" style="text-align:center">
+        <h3 style="margin-bottom:0.25rem">Ignored</h3>
+        <p class="empty-hint" style="margin-bottom:0.5rem">Peers whose posts and profiles are hidden from Feed, Messages, and Discover. Local-only; nothing on the wire says you've ignored them.</p>
+        <div id="ignored-list" style="text-align:left"></div>
+      </div>
+
       <div class="section-card" style="text-align:center">
         <h3 style="margin-bottom:0.25rem">Updates</h3>
         <p class="empty-hint" style="margin-bottom:0.5rem">Network-wide release announcements are signed by the bootstrap anchor and arrive via the CDN. Choose which channel to follow.</p>