chore(v1.1.7): fix clippy --all-targets warnings

Clears the workspace under `clippy --all-targets --all-features
-D warnings`. Four were pre-existing at v1.1.6 HEAD (latent finding,
see HANDBACK): double_must_use on realtime_router, map_unwrap_or in
pubsub_service, redundant_closure in topic_repo, needless_raw_string in
a subscriber-token test. The rest are v1.1.7 nits (needless_borrow +
semicolon in the dead-letter / realtime-migration code).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

crates/picloud/src/lib.rs

@@ -198,12 +198,14 @@ pub async fn build_app(
     // plaintext column is dropped in v1.1.8.
     match app_secrets_repo.migrate_plaintext_keys().await {
         Ok(0) => {}
-        Ok(n) => tracing::info!(
-            migrated = n,
-            "encrypted plaintext realtime signing keys at rest"
-        ),
+        Ok(n) => {
+            tracing::info!(
+                migrated = n,
+                "encrypted plaintext realtime signing keys at rest"
+            );
+        }
         Err(e) => {
-            tracing::error!(error = %e, "failed to encrypt realtime signing keys (continuing)")
+            tracing::error!(error = %e, "failed to encrypt realtime signing keys (continuing)");
         }
     }
     let realtime_authority: Arc<dyn RealtimeAuthority> = Arc::new(RealtimeAuthorityImpl::new(