refactor: split backend into standalone server project

Remove embedded frontend and workflow editor assets, add standalone API deployment configuration, and retain the current backend service updates.

docker/agent-desk-sqlite-lancedb.yaml

@@ -2,10 +2,11 @@ language: zh-CN
 
 server:
   port: 8083
+  frontendUrl: http://127.0.0.1:3000
   cors:
     allowedOrigins:
-      - http://localhost:8083
-      - http://127.0.0.1:8083
+      - http://localhost:3000
+      - http://127.0.0.1:3000
 
 db:
   type: sqlite
@@ -35,7 +36,7 @@ storage:
   maxUploadSizeMB: 20
   local:
     root: /app/data/storage
-    baseUrl: /storage
+    baseUrl: http://127.0.0.1:8083/storage
   oss:
     endpoint: ""
     bucket: ""