Cleanup skill logic files and update deployment scripts

refactor: remove hardcoded ai.jerxie.com references ...

- Dynamically generate CORS origins based on HUB_PUBLIC_URL.\n- Use window.location.origin in frontend provision scripts.\n- Set localhost/127.0.0.1 as default configurations for local nodes, docker-compose, and spawning scripts.

feat(ui): convert clear chat confirm alert to custom modal ...

- Removed window.confirm for clearing chat history.\n- Added a modern React modal to prevent page flashing and improve UX.

feat(explorer): add image support, upload, and download to file explorer ...

- Backend: Added /fs/upload (multipart) and /fs/download (streaming) endpoints.\n- Backend: Fixed binary handling in fs_touch.\n- Frontend: Added nodeFsUpload and nodeFsDownloadBlob to apiService.\n- Frontend: Integrated image detection and preview lightbox.\n- Frontend: Added file upload action for folders and root.\n- Frontend: Added individual file download buttons.

feat(provision): dynamic browser support and installer resiliency ...

- Added browser support toggle to one-liner UI.\n- Updated provision endpoint to handle skip_browsers and disable skill in config.\n- Improved installer to handle --skip-browsers and avoid hardcoded URLs.\n- Added safeguards to browser skill to prevent whole-agent crashes.\n- Enabled invite_token auth for agent updates.\n- Bumps version to 1.0.15.

fix(nodes): wrap provisioning URL in quotes to prevent shell globbing

feat(nodes): add headless one-liner provisioning ...

- New /api/v1/nodes/provision/{node_id} endpoint returns a python install script.\n- New /api/v1/agent/installer endpoint serves the bootstrap_installer.py script.\n- UI updated with code snippet and copy-to-clipboard for rapid headless deployment.

refactor: re-org frontend folder structure to simply be 'frontend' ...

- Moved ui/client-app to frontend/

- Updated README and documentation references

- Updated docker-compose, local run scripts, and remote deploy scripts to point to new frontend location