refactor: type safety + dedup cleanup across 13 code smells

- typed PagedResponse/CreatedApiKeyResponse/NotificationSummaryResponse replace json! blocks
- extract TagRow/ApiKeyRow/OutboxRow to module level, top_friend uses sqlx flatten
- add should_broadcast() helper, inline dead let bindings in federation_event
- add UploadContext struct, extract_upload_field, wants_activity_json helpers
- rename PostgresFederationRepository→PgFederationRepository, PostgresApUserRepository→PgApUserRepository
- add IntoAnyhow trait replacing ~30 .map_err(|e| anyhow!(e)) calls
- extract build_ap_service shared between bootstrap and worker factories
- add postgres/constants.rs, PartialEq+Eq on PasswordHash

crates/adapters/activitypub/src/lib.rs

@@ -11,3 +11,48 @@ pub use port::{
 };
 pub use service::ApFederationAdapter;
 pub use urls::ThoughtsUrls;
+
+use domain::ports::RemoteActorConnectionRepository;
+use k_ap::ActivityPubService;
+use std::sync::Arc;
+
+pub struct ApServiceConfig {
+    pub base_url: String,
+    pub activity_repo: Arc<dyn k_ap::ActivityRepository>,
+    pub follow_repo: Arc<dyn k_ap::FollowRepository>,
+    pub actor_repo: Arc<dyn k_ap::ActorRepository>,
+    pub blocklist_repo: Arc<dyn k_ap::BlocklistRepository>,
+    pub user_repo: Arc<dyn k_ap::ApUserRepository>,
+    pub ap_handler: Arc<ThoughtsObjectHandler>,
+    pub connections_repo: Arc<dyn RemoteActorConnectionRepository>,
+    pub event_publisher: Option<Arc<dyn k_ap::data::EventPublisher>>,
+    pub allow_registration: bool,
+    pub debug: bool,
+}
+
+pub async fn build_ap_service(
+    cfg: ApServiceConfig,
+) -> (Arc<ActivityPubService>, Arc<ApFederationAdapter>) {
+    let mut builder = ActivityPubService::builder(cfg.base_url)
+        .activity_repo(cfg.activity_repo)
+        .follow_repo(cfg.follow_repo)
+        .actor_repo(cfg.actor_repo)
+        .blocklist_repo(cfg.blocklist_repo)
+        .user_repo(cfg.user_repo)
+        .content_reader(cfg.ap_handler.clone())
+        .object_handler(cfg.ap_handler)
+        .allow_registration(cfg.allow_registration)
+        .software_name("thoughts")
+        .debug(cfg.debug);
+    if let Some(publisher) = cfg.event_publisher {
+        builder = builder.event_publisher(publisher);
+    }
+    let raw = Arc::new(
+        builder
+            .build()
+            .await
+            .expect("Failed to build ActivityPubService"),
+    );
+    let adapter = Arc::new(ApFederationAdapter::new(raw.clone(), cfg.connections_repo));
+    (raw, adapter)
+}