Design doc audit: update badges, fix outdated descriptions, add CDN/replication docs

Badge updates:
- BlobHeader: Planned → Complete (has receipt/comment slots, reactions, policy)
- LAN Discovery: Planned → Complete (iroh mDNS integration)
- UPnP TCP: Planned → Complete (both UDP+TCP renewal cycles)
- HTTP Post Delivery: added Complete badge

Description fixes:
- Share links: removed hostlist encoding, added tiered serving (redirect → punch → proxy)
- Eviction formula: added share_boost factor (+100 for 3+ downstream)
- Message types table: added ReplicationRequest/Response (0xE1/0xE2), count 41 → 49
- Engagement: added tombstone propagation description

New sections:
- Device roles & bandwidth budgets (Intermittent/Available/Persistent)
- Active CDN replication (10-min cycle, target prioritization, graceful degradation)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

crates/tauri-app/gen/schemas/capabilities.json

@@ -1 +1 @@
-{"default":{"identifier":"default","description":"Default capability for the main window","local":true,"windows":["main"],"permissions":["core:default","notification:default","notification:allow-is-permission-granted","notification:allow-request-permission","notification:allow-notify","notification:allow-check-permissions","notification:allow-show"]}}
+{"default":{"identifier":"default","description":"Default capability for the main window","local":true,"windows":["main"],"permissions":["core:default","notification:default","notification:allow-is-permission-granted","notification:allow-request-permission","notification:allow-notify","notification:allow-check-permissions","notification:allow-show","notification:allow-cancel","notification:allow-remove-active"]}}