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.

.vscode/tasks.json

@@ -2,29 +2,14 @@
   "version": "2.0.0",
   "tasks": [
     {
-      "label": "web:dev",
+      "label": "server:dev",
       "type": "shell",
-      "command": "pnpm dev",
+      "command": "make dev",
       "options": {
-        "cwd": "${workspaceFolder}/web"
+        "cwd": "${workspaceFolder}"
       },
       "isBackground": true,
-      "presentation": {
-        "reveal": "always",
-        "panel": "dedicated",
-        "group": "web"
-      },
-      "problemMatcher": {
-        "owner": "custom",
-        "pattern": {
-          "regexp": "."
-        },
-        "background": {
-          "activeOnStart": true,
-          "beginsPattern": ".",
-          "endsPattern": "Ready in|Local:"
-        }
-      }
+      "problemMatcher": []
     }
   ]
 }