feat(engine): wire reflection pipeline + trace analysis into thread lifecycle

After every thread completes, ThreadManager now automatically runs:

1. Retrospective trace analysis (non-LLM, always):
   - Detects 8 issue categories (tool errors, code errors, missing
     outputs, excessive steps, hallucination risk, etc.)
   - Logs issues at warn level when found

2. Trace file recording (when ENGINE_V2_TRACE=1):
   - Writes full JSON trace to engine_trace_{timestamp}.json

3. LLM reflection (when enable_reflection=true):
   - Calls reflection pipeline to produce Summary, Lesson, Issue docs
   - Saves docs to store for future context retrieval
   - Enabled by default in the bridge router

All three run inside the spawned tokio task after exec.run() completes,
before saving the final thread state. No external wiring needed.

Removed duplicate trace recording from the router — it's now handled
by ThreadManager automatically.

Co-Authored-By: Claude Opus 4.6 (1M context) <[email protected]>

src/bridge/router.rs

@@ -168,7 +168,10 @@ pub async fn handle_with_engine(
             content,
             state.default_project_id,
             &message.user_id,
-            ThreadConfig::default(),
+            ThreadConfig {
+                enable_reflection: true,
+                ..ThreadConfig::default()
+            },
         )
         .await
         .map_err(|e| {
@@ -222,14 +225,9 @@ pub async fn handle_with_engine(
         .record_thread_outcome(conv_id, thread_id, &outcome)
         .await;
 
-    // Trace recording + retrospective analysis
-    if ironclaw_engine::executor::trace::is_trace_enabled()
-        && let Ok(Some(thread)) = state.store.load_thread(thread_id).await
-    {
-        let trace = ironclaw_engine::executor::trace::build_trace(&thread);
-        ironclaw_engine::executor::trace::log_trace_summary(&trace);
-        ironclaw_engine::executor::trace::write_trace(&trace);
-    }
+    // Note: trace recording, retrospective analysis, and LLM reflection
+    // all run automatically inside ThreadManager after the thread completes.
+    // See crates/ironclaw_engine/src/runtime/manager.rs.
 
     // Convert outcome to response
     match outcome {