feat(ap): ActivityPub spec compliance and profile completeness

Phase 1 — spec compliance:
- Add AS_PUBLIC constant; add to/cc fields to CreateActivity, DeleteActivity,
  UpdateActivity, AddActivity; populate on all broadcast call sites
- Add @context to outbox CreateActivity items
- Set manuallyApprovesFollowers: true to match actual Pending follow flow
- Gate PermissiveVerifier behind FEDERATION_DEBUG env var
- Add updated timestamp to Person actor JSON
- Improve actor update delivery logging

Phase 2a Batch 1 — AP layer:
- Add /inbox shared inbox route; add endpoints.sharedInbox to Person
- Paginate followers and following collections (20/page, OrderedCollectionPage)

Phase 2a Batch 2 — profile completeness:
- DB migrations: banner_path, also_known_as columns; user_profile_fields table
- ProfileField value object; UserProfileFieldsRepository port
- Banner image upload (stored via image-converter, surfaced as image in Person)
- alsoKnownAs field in Person (account migration support)
- Custom profile fields (up to 4 PropertyValue attachments in Person)
- Profile settings UI: banner preview/upload, alsoKnownAs input, fields form
- PUT /api/v1/profile/fields API endpoint

crates/adapters/sqlite/src/lib.rs

@@ -19,6 +19,7 @@ mod migrations;
 mod models;
 mod persons;
 mod profile;
+mod profile_fields;
 mod users;
 mod watchlist;
 
@@ -32,9 +33,16 @@ pub use import_profile::SqliteImportProfileRepository;
 pub use import_session::SqliteImportSessionRepository;
 pub use persons::{SqlitePersonAdapter, create_person_adapter};
 pub use profile::SqliteMovieProfileRepository;
+pub use profile_fields::SqliteProfileFieldsRepository;
 pub use users::SqliteUserRepository;
 pub use watchlist::SqliteWatchlistRepository;
 
+pub fn create_profile_fields_repo(
+    pool: sqlx::SqlitePool,
+) -> std::sync::Arc<dyn domain::ports::UserProfileFieldsRepository> {
+    std::sync::Arc::new(SqliteProfileFieldsRepository::new(pool))
+}
+
 fn format_year_month(ym: &str) -> String {
     let parts: Vec<&str> = ym.splitn(2, '-').collect();
     if parts.len() != 2 {