feat(dashboard): embedded FastAPI backend with REST API + WebSocket

- FastAPI runs in MeshAI asyncio loop (no separate process)
- REST API: /api/status, /api/health, /api/nodes, /api/edges,
  /api/regions, /api/sources, /api/config, /api/alerts
- WebSocket at /ws/live pushes health updates and alerts
- Config CRUD: GET/PUT per section with validation and save
- DashboardConfig with port/host in config.yaml

meshai/config.py

@@ -257,6 +257,16 @@ class MeshIntelligenceConfig:
     alert_rules: AlertRulesConfig = field(default_factory=AlertRulesConfig)
 
 
+
+
+@dataclass
+class DashboardConfig:
+    """Web dashboard settings."""
+
+    enabled: bool = True
+    port: int = 8080
+    host: str = "0.0.0.0"
+
 @dataclass
 class Config:
     """Main configuration container."""
@@ -274,6 +284,7 @@ class Config:
     knowledge: KnowledgeConfig = field(default_factory=KnowledgeConfig)
     mesh_sources: list[MeshSourceConfig] = field(default_factory=list)
     mesh_intelligence: MeshIntelligenceConfig = field(default_factory=MeshIntelligenceConfig)
+    dashboard: DashboardConfig = field(default_factory=DashboardConfig)
 
     _config_path: Optional[Path] = field(default=None, repr=False)