feat(services): enhance services with rollback and observability

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

backend/app/services/rollback_controller.py

@@ -0,0 +1,25 @@
+from __future__ import annotations
+
+from app.config import settings
+
+
+FEATURE_FLAG_NAMES = (
+    "ENABLE_RETROSPECTIVE",
+    "ENABLE_SESSION_RETROSPECTIVE_SEARCH",
+    "ENABLE_RUNTIME_SKILL_SHORTLIST",
+    "ENABLE_LEARNING_SIGNALS",
+    "ENABLE_SKILL_PROMOTION",
+    "ENABLE_LEARNED_SKILL_LOADING",
+    "ENABLE_PARALLEL_TASK_GRAPH",
+)
+
+
+class RollbackController:
+    def snapshot_flags(self) -> dict[str, bool]:
+        return {
+            flag_name: bool(getattr(settings, flag_name, False))
+            for flag_name in FEATURE_FLAG_NAMES
+        }
+
+    def is_enabled(self, flag_name: str) -> bool:
+        return bool(getattr(settings, flag_name, False))