chore: reorganize repo — legacy packages to legacy-packages/, templates to examples/

- Move 15 old workflow-* packages to legacy-packages/ (inactive, preserved for reference)
- Rename templates/ → examples/ for clarity
- Rewrite docs/architecture.md to reflect current uwf architecture
- Active packages remain in packages/: cli-uwf, uwf-agent-hermes, uwf-agent-kit, uwf-moderator, uwf-protocol, workflow-util

小橘 🍊（NEKO Team）

packages/workflow-util-agent/package.json

@@ -1,30 +0,0 @@
-{
-  "name": "@uncaged/workflow-util-agent",
-  "version": "0.5.0-alpha.4",
-  "files": [
-    "src",
-    "dist",
-    "package.json"
-  ],
-  "type": "module",
-  "types": "src/index.ts",
-  "exports": {
-    ".": {
-      "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-util": "workspace:^",
-    "zod": "^4.0.0"
-  },
-  "publishConfig": {
-    "access": "public"
-  }
-}