feat: release 2.2.0 with PC-only tests and execution reliability fixes

Unify task scheduling and queue state, fix Android input and observation recovery, preserve screenshot paths, and match final review criteria accurately. Add collapsible copyable results and publish the complete 2.1.0 upgrade notes. Validation: 3189 backend tests, 326 frontend tests, 24 client tests, production build and quality gates.

artemis/runtime/task_control.py

@@ -100,6 +100,12 @@ def write_control_state(session_id: str, status: str, *, reset: bool = False, **
             "timing": timing,
         },
     )
+    if status == "running" and (control_dir(session_id) / "status.json").is_file():
+        from artemis.runtime import trace_store
+
+        # The worker reaches this state only after acquiring its execution lease.
+        # Admission stays pending until then; never revive a cancelled/finished task.
+        trace_store.update_trace_status(session_id, "running", expected_status="pending")
 
 
 def request_pause(session_id: str, *, reason: str | None = None) -> None: