feat(swarm): DeckyConfig.host_uuid + fix agent log/status field refs

- decnet.models.DeckyConfig grows an optional 'host_uuid' (the SwarmHost
  that runs this decky). Defaults to None so legacy unihost state files
  deserialize unchanged.
- decnet.agent.executor: replace non-existent config.name references
  with config.mode / config.interface in logs and status payload.
- tests/swarm/test_state_schema.py covers legacy-dict roundtrip, field
  default, and swarm-mode assignments.

decnet/agent/executor.py

@@ -21,7 +21,10 @@ log = get_logger("agent.executor")
 async def deploy(config: DecnetConfig, dry_run: bool = False, no_cache: bool = False) -> None:
     """Run the blocking deployer off-loop. The deployer itself calls
     save_state() internally once the compose file is materialised."""
-    log.info("agent.deploy name=%s deckies=%d", config.name, len(config.deckies))
+    log.info(
+        "agent.deploy mode=%s deckies=%d interface=%s",
+        config.mode, len(config.deckies), config.interface,
+    )
     await asyncio.to_thread(_deployer.deploy, config, dry_run, no_cache, False)
 
 
@@ -39,7 +42,7 @@ async def status() -> dict[str, Any]:
     config, _compose_path = state
     return {
         "deployed": True,
-        "name": getattr(config, "name", None),
+        "mode": config.mode,
         "compose_path": str(_compose_path),
         "deckies": [d.model_dump() for d in config.deckies],
     }

decnet/models.py

@@ -99,6 +99,9 @@ class DeckyConfig(BaseModel):
     mutate_interval: int | None = None  # automatic rotation interval in minutes
     last_mutated: float = 0.0     # timestamp of last mutation
     last_login_attempt: float = 0.0 # timestamp of most recent interaction
+    # SWARM: the SwarmHost.uuid that runs this decky. None in unihost mode
+    # so existing state files deserialize unchanged.
+    host_uuid: str | None = None
 
     @field_validator("services")
     @classmethod