feat: image storage generalization, user profile, and federation polish

- Replace PosterStorage with generic ImageStorage port (IMAGE_STORAGE_BACKEND/PATH env vars)
- Rename poster-storage crate to image-storage; serve at /images/{*key}
- Add bio and avatar_path to User model (migration 0009_user_profile)
- update_profile use case with avatar upload, mime validation, old avatar cleanup
- GET/PUT /api/v1/profile and GET/POST /settings/profile HTML page
- Enrich AP Person actor with summary, icon, url, discoverable fields
- Store remote actor avatar_url (migration 0010_ap_remote_actor_avatar)
- Shared inbox delivery via collect_inboxes deduplication
- Broadcast Update(Person) to followers on UserUpdated event
- Paginated outbox: OrderedCollection + OrderedCollectionPage with cursor
- Announce/boost tracking in ap_announces table (migration 0011_ap_announces)

Cargo.toml

@@ -4,7 +4,7 @@ members = [
     "crates/adapters/event-publisher",
     "crates/adapters/metadata",
     "crates/adapters/poster-fetcher",
-    "crates/adapters/poster-storage",
+    "crates/adapters/image-storage",
     "crates/adapters/poster-sync",
     "crates/adapters/rss",
     "crates/adapters/sqlite",
@@ -59,7 +59,7 @@ presentation = { path = "crates/presentation" }
 auth = { path = "crates/adapters/auth" }
 metadata = { path = "crates/adapters/metadata" }
 poster-fetcher = { path = "crates/adapters/poster-fetcher" }
-poster-storage = { path = "crates/adapters/poster-storage" }
+image-storage = { path = "crates/adapters/image-storage" }
 poster-sync = { path = "crates/adapters/poster-sync" }
 event-publisher = { path = "crates/adapters/event-publisher" }
 rss = { path = "crates/adapters/rss" }