feat: prepare 2.2.0 with UI and execution fixes

Add dark theme, richer Markdown and readable plugin results.
Improve Android input evidence, response integrity and diagnostics.
Unify lifecycle, guidance receipts and evidence sources across clients.
Keep direct action dispatch without an added AI quota approval layer.
Align version metadata at 2.2.0 and bundle Helper 1.2.2.

Validation: 3063 backend tests before the version bump; 44 after.
Frontend: 317 tests and production build passed.

artemis/data_engine/storage.py

@@ -963,6 +963,19 @@ class StorageManager:
                 )
         return traces
 
+    def get_latest_trace_payload(self, session_id: UUID | str, name: str) -> dict | None:
+        """Read a durable task-owned execution ledger from the existing trace store."""
+        with self._get_connection() as conn:
+            row = conn.execute(
+                "SELECT payload FROM traces WHERE session_id = ? AND name = ? "
+                "ORDER BY timestamp DESC LIMIT 1",
+                (str(session_id), name),
+            ).fetchone()
+        if not row or not row["payload"]:
+            return None
+        value = json.loads(row["payload"])
+        return value if isinstance(value, dict) else None
+
     def get_steps_with_traces(self, session_id: UUID) -> list[tuple[StepRecord, list[TraceRecord]]]:
         """Retrieve all steps and their associated traces for a session."""
         steps = self.get_steps(session_id)