ClearChat Home v1.3.2 - Avatar Upload Polish

Changes:
- Adds a real Settings -> Agent Avatar upload workflow.
- Adds preview of current agent avatar.
- Uploads avatar images to uploads/avatars automatically.
- Automatically updates the Agent Avatar URL after upload.
- Allows JPG, PNG, WebP, and GIF images under 2 MB.
- Cleans the release package to avoid nested clearchat folders.

Install/Update Notes:
- Back up your existing ClearChat folder and database first.
- Use Admin -> Update to upload the ZIP, or replace files manually.
- Keep your existing config files and uploaded avatars.
