feat: Implement multi-node support with MQTT and mDNS for service discovery and coordination

castle-api/src/castle_api/models.py

@@ -28,6 +28,7 @@ class ComponentSummary(BaseModel):
     system_dependencies: list[str] = []
     schedule: str | None = None
     installed: bool | None = None
+    node: str | None = None
 
 
 class ComponentDetail(ComponentSummary):
@@ -50,13 +51,55 @@ class StatusResponse(BaseModel):
     statuses: list[HealthStatus]
 
 
+class GatewayRoute(BaseModel):
+    """A single route in the gateway's reverse proxy table."""
+
+    path: str
+    target_port: int
+    component: str
+    node: str
+
+
 class GatewayInfo(BaseModel):
     """Gateway configuration summary."""
 
     port: int
+    hostname: str
     component_count: int
     service_count: int
     managed_count: int
+    routes: list[GatewayRoute] = []
+
+
+class NodeSummary(BaseModel):
+    """Summary of a discovered node in the mesh."""
+
+    hostname: str
+    gateway_port: int
+    deployed_count: int
+    service_count: int
+    is_local: bool = False
+    online: bool = True
+    is_stale: bool = False
+    last_seen: float | None = None
+
+
+class NodeDetail(NodeSummary):
+    """Full detail for a node, including its deployed components."""
+
+    deployed: list[ComponentSummary] = []
+
+
+class MeshStatus(BaseModel):
+    """Current state of the mesh coordination layer."""
+
+    enabled: bool = False
+    mqtt_connected: bool = False
+    mqtt_broker_host: str | None = None
+    mqtt_broker_port: int | None = None
+    mdns_enabled: bool = False
+    peer_count: int = 0
+    peers: list[str] = []
 
 
 class ServiceActionResponse(BaseModel):