feat: extract in-process MCP action layer, concurrent task dispatch, and spawn/reconcile hardening

- Extract device action execution into artemis/mcp action layer:
  typed ActionResult, capability manifest with startup validation,
  AdbActuator as the single physical implementation, in-memory
  ActionSession (replaces stdio subprocess MCP in validator), and
  McpActionExecutor preserving the legacy executor contract.
  adb_server keeps its external stdio/SSE surface unchanged and now
  reuses the actuator implementation; import-time side effects moved
  into configure_stdio_mode().
- Capability-gated prompt assembly (prompt_assembly.py): tool enums and
  teaching segments render per available backend tools; full-set output
  is byte-identical to the previous static text (locked by tests).
- Admin console task queue: serial worker replaced by a per-device
  concurrent dispatcher (ARTEMIS_CONCURRENCY_MODE=global restores
  serial semantics), per-session cancellation, strict device binding on
  enqueue, unified stdio piping with tee to trace stdout.log, and
  shutdown cleanup of all active runs. Fix _pid_exists exception order
  so PermissionError is treated as alive.
- mcp_server reliability: spawn watchdog kills runners stuck before
  interpreter startup and releases device reservations; task state
  reconcile uses psutil liveness, prefers runner-reported pids, and
  adds a 45s startup grace to stop false failure reports on Windows;
  conversation_id is now optional end-to-end; explicit device_serial is
  validated at submission.
- CLI install now writes ~/.claude/rules/artemis.md for Claude Code and
  migrates/removes the legacy CLAUDE.md injection block; ~/.claude.json
  is never rewritten when it fails to parse.
- Tests: Windows-portable stdio lifecycle and path assertions; new
  suites for action layer, prompt assembly, spawn watchdog, and task
  reconcile (895 passed, 3 skipped).

tests/unit/mcp/test_task_reconcile.py

@@ -0,0 +1,133 @@
+# Copyright 2026 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""Regression tests for mobile_manage_task's state reconciliation.
+
+Guards the invariants restored after the reconcile rewrite:
+- a DB terminal verdict never overrides a status.json that already reached its
+  own terminal state (a completed task must keep its result),
+- except to correct a previously liveness-inferred failure,
+- and a task without a recorded pid (daemon dispatch) is never inferred dead.
+"""
+
+import sqlite3
+import time
+
+import pytest
+
+import mcp_server.tools.task_manager as task_manager
+from mcp_server.tools.task_manager import _LIVENESS_FAILURE_ERROR, _reconcile_task_state
+
+
+@pytest.fixture
+def no_persistence(monkeypatch):
+    """Keep reconciliation in-memory: no DB, no status writes, no lock queries."""
+    monkeypatch.setattr(task_manager, "_find_data_engine_db", lambda: None)
+    monkeypatch.setattr(task_manager, "_session_tracked_by_lock", lambda _tid: False)
+    monkeypatch.setattr(task_manager.trace_store, "write_status", lambda *_a, **_k: None)
+    monkeypatch.setattr(
+        task_manager.trace_store, "update_trace_status", lambda *_a, **_k: None
+    )
+    monkeypatch.setattr(task_manager, "notify", lambda *_a, **_k: None)
+
+
+def _db_with_session(tmp_path, trace_id: str, status: str, pid: int | None = 4242):
+    db_path = tmp_path / "artemis.db"
+    conn = sqlite3.connect(db_path)
+    conn.execute(
+        "CREATE TABLE sessions (session_id TEXT, status TEXT, pid INTEGER, start_time REAL)"
+    )
+    conn.execute(
+        "INSERT INTO sessions VALUES (?, ?, ?, ?)", (trace_id, status, pid, time.time())
+    )
+    conn.commit()
+    conn.close()
+    return str(db_path)
+
+
+@pytest.fixture
+def use_db(tmp_path, monkeypatch, no_persistence):
+    def _install(trace_id: str, status: str, pid: int | None = 4242):
+        db_path = _db_with_session(tmp_path, trace_id, status, pid)
+        monkeypatch.setattr(task_manager, "_find_data_engine_db", lambda: db_path)
+
+    return _install
+
+
+def test_db_failed_never_overrides_completed_status(use_db):
+    use_db("t1", "failed")
+    status_data = {"status": "completed", "result": "the answer", "pid": 111}
+
+    current_status, _pid, is_alive = _reconcile_task_state("t1", status_data)
+
+    assert current_status == "completed"
+    assert status_data["status"] == "completed"
+    assert status_data["result"] == "the answer"
+    assert is_alive is False
+
+
+def test_db_verdict_corrects_liveness_inferred_failure(use_db):
+    use_db("t2", "completed")
+    status_data = {"status": "failed", "error": _LIVENESS_FAILURE_ERROR, "pid": 111}
+
+    current_status, _pid, _is_alive = _reconcile_task_state("t2", status_data)
+
+    assert current_status == "completed"
+    assert status_data["error"] is None
+
+
+def test_db_never_overrides_user_cancellation(use_db):
+    use_db("t3", "completed")
+    status_data = {"status": "cancelled", "pid": 111}
+
+    current_status, _pid, _is_alive = _reconcile_task_state("t3", status_data)
+
+    assert current_status == "cancelled"
+
+
+def test_pidless_running_task_is_assumed_alive(no_persistence):
+    # Daemon dispatch writes no pid into status.json; liveness must not be
+    # inferred even long past the startup grace window.
+    status_data = {"status": "running", "start_time": time.time() - 3600}
+
+    current_status, _pid, is_alive = _reconcile_task_state("t4", status_data)
+
+    assert current_status == "running"
+    assert is_alive is True
+    assert status_data.get("error") is None
+
+
+def test_dead_pid_past_grace_is_marked_failed(no_persistence, monkeypatch):
+    monkeypatch.setattr(task_manager, "_pid_alive", lambda _pid: False)
+    status_data = {
+        "status": "running",
+        "pid": 99999,
+        "start_time": time.time() - 3600,
+    }
+
+    current_status, _pid, is_alive = _reconcile_task_state("t5", status_data)
+
+    assert current_status == "failed"
+    assert status_data["error"] == _LIVENESS_FAILURE_ERROR
+    assert is_alive is False
+
+
+def test_dead_pid_within_grace_is_assumed_alive(no_persistence, monkeypatch):
+    monkeypatch.setattr(task_manager, "_pid_alive", lambda _pid: False)
+    status_data = {"status": "running", "pid": 99999, "start_time": time.time()}
+
+    current_status, _pid, is_alive = _reconcile_task_state("t6", status_data)
+
+    assert current_status == "running"
+    assert is_alive is True