fix(modes): accept code_review as alias for codereview

External callers (lakehouse observer.ts) escalate to /api/run with mode
"code_review" (underscored), but the canonical registered mode is "codereview",
so those calls hit the unknown-mode 400 and silently dropped. Normalize the alias
right after reading the mode so it validates and dispatches via RUNNERS.

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

llm_team_ui.py

@@ -10769,6 +10769,11 @@ def run_team():
         return jsonify({"error": "Request body required"}), 400
 
     mode = config.get("mode", "")
+    # Alias: external callers (e.g. lakehouse observer.ts) escalate to the underscored
+    # `code_review`, but the canonical registered mode is `codereview` — normalize so
+    # those calls dispatch via RUNNERS instead of silently failing the 400 below.
+    if mode == "code_review":
+        mode = "codereview"
     if not mode:
         return jsonify({"error": "Mode is required"}), 400