feat(host-agent): wire skill sync + inventory report into app lifecycle

Adds host_agent/skill_sync.py (HostAgentSkillSync) which constructs the
synced + local skill stores, the Cloud API sync client, and the runner,
then drives them on the host-agent lifecycle: incremental per-host pull
into the synced catalog, fork-on-revocation, and a best-effort local-
skill inventory report to the Cloud (design D7). Wired into
create_application + run_async start/stop. Host-agent suite green
(219 passed).

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

apps/device-host-agent/host_agent/app.py

@@ -24,6 +24,7 @@ from host_agent.local_account import LocalAccountStore
 from host_agent.policy_cache import HostPolicyCacheStore
 from host_agent.processor import AssignmentProcessingResult, AssignmentProcessor
 from host_agent.retention import prune_task_history
+from host_agent.skill_sync import HostAgentSkillSync
 from host_agent.status import AgentStatusTracker
 from host_agent.web.app import create_console_app
 from host_agent.web.auth import SessionManager
@@ -42,6 +43,7 @@ class HostAgentApplication:
     console_enrollment_client: HostAgentEnrollmentClient | None = None
     dependency_supervisor: DependencySupervisor | None = None
     instance_lock: InstanceLock | None = None
+    skill_sync: HostAgentSkillSync | None = None
 
     def run(self) -> None:
         asyncio.run(self.run_async())
@@ -60,6 +62,8 @@ class HostAgentApplication:
             )
         heartbeat_stop = asyncio.Event()
         heartbeat_task = asyncio.create_task(self.heartbeat.run(heartbeat_stop))
+        if self.skill_sync is not None:
+            self.skill_sync.start()
         console_task = (
             asyncio.create_task(self.console_server.serve())
             if self.console_server is not None
@@ -110,6 +114,8 @@ class HostAgentApplication:
             finally:
                 if self.console_enrollment_client is not None:
                     self.console_enrollment_client.close()
+                if self.skill_sync is not None:
+                    self.skill_sync.stop()
                 await self.client.aclose()
                 if self.instance_lock is not None:
                     self.instance_lock.release()
@@ -263,6 +269,9 @@ def create_application(
             dependency_supervisor = DependencySupervisor.from_host_agent_config(
                 resolved_config
             )
+        skill_sync: HostAgentSkillSync | None = None
+        if resolved_config.host_id and resolved_config.token:
+            skill_sync = HostAgentSkillSync(resolved_config)
         return HostAgentApplication(
             client=client,
             heartbeat=heartbeat,
@@ -271,6 +280,7 @@ def create_application(
             console_enrollment_client=console_enrollment_client,
             dependency_supervisor=dependency_supervisor,
             instance_lock=instance_lock,
+            skill_sync=skill_sync,
         )
     except BaseException:
         instance_lock.release()