[Feature Request] Cleaner workspace — move all service folders into `.qwenpaw` hidden directory

### Problem

When creating a new agent, QwenPaw creates many service folders in the workspace root:
`backup/`, `browser/`, `dialog/`, `file_store/`, `skills/`, `tool_result/`, `memory/`, `sessions/`, `customized_skills/`, etc.

This makes the workspace very cluttered.

### Suggested Solution

By default (or via config), store all internal data inside one hidden folder:
workspace/
├─ AGENTS.md
├─ SOUL.md
├─ agent.json
├─ .qwenpaw/ ← all internal data here
│ ├── backup/
│ ├── browser/
│ ├── skills/
│ ├── memory/
│ ├── tool_result/
│ └── ...
└── .gitignore
textIt would be great to have this as default behavior (similar to `.hermes/`, `.cursor/`, `.venv/` etc.).

### Optional

Add setting in `agent.json`:
```json
"internal_dir": ".qwenpaw"
```

Best regards,
Ivan Litovchenko