chore: bump all packages to 0.4.0, fix exports for publish

- All @uncaged/* packages → 0.4.0
- Internal deps: workspace:* → workspace:^ (resolves to ^0.4.0 on publish)
- Fix exports: add 'bun' condition for local dev (src), 'import' for consumers (dist)
- Remove stale 'main: src/index.ts' from 6 packages
- Fix publish.sh topo sort to match workspace:^ prefix

星月 <xingyue@shazhou.work>

packages/workflow-util-agent/package.json

@@ -1,25 +1,25 @@
 {
   "name": "@uncaged/workflow-util-agent",
-  "version": "0.3.21",
+  "version": "0.4.0",
   "files": [
     "dist",
     "package.json"
   ],
   "type": "module",
-  "main": "src/index.ts",
   "types": "src/index.ts",
   "exports": {
     ".": {
-      "types": "./src/index.ts",
-      "default": "./src/index.ts"
+      "bun": "./src/index.ts",
+      "types": "./dist/index.d.ts",
+      "import": "./dist/index.js"
     }
   },
   "scripts": {
     "test": "bun test"
   },
   "dependencies": {
-    "@uncaged/workflow-runtime": "workspace:*",
-    "@uncaged/workflow-cas": "workspace:*",
+    "@uncaged/workflow-runtime": "workspace:^",
+    "@uncaged/workflow-cas": "workspace:^",
     "zod": "^4.0.0"
   }
 }