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).

artemis/agents/operator/prompt_builder.py

@@ -39,12 +39,18 @@ class OperatorPromptBuilder:
     """Builds prompt messages and multimodal contents for the Operator Agent."""
 
     @classmethod
-    def build_system_message(cls, template_name: str = "main_template") -> str:
+    def build_system_message(
+        cls,
+        template_name: str = "main_template",
+        available_tools: frozenset[str] | None = None,
+    ) -> str:
         from artemis.agents.operator.prompts import apply_operator_prompt_contract
 
         prompts = load_operator_prompts()
         try:
-            return apply_operator_prompt_contract(prompts[template_name])
+            return apply_operator_prompt_contract(
+                prompts[template_name], available_tools=available_tools
+            )
         except KeyError as exc:
             raise ValueError(f"Unknown Operator template: {template_name}") from exc