Features added:
- Connection status indicator (green=connected, yellow=connecting, red=disconnected)
- Exponential backoff reconnection (1s → 2s → 4s → ... → 30s max)
- Typing indicators showing who is typing (up to 3 users, with overflow count)
- Message status (⋯ sending, ✓ sent, ✗ failed with retry option)
- Jump-to-bottom button with unread message count badge
- Smart scroll preservation (stays in place unless already at bottom)
- Optimistic UI for sent messages (appears immediately, updates with real status)
- Backend support for broadcasting typing events to other users
- Breadcrumb navigation on board and thread pages (Home › Boards › Board › Thread)
- Back buttons to return to parent page (with arrow icon and hover effects)
- Scroll-to-top button appears after scrolling 300px (smooth animation)
- Keyboard shortcuts: Ctrl+Enter submits forms from textarea, Esc clears focus and closes notifications
- Optimistic UI for like/dislike buttons (immediate visual feedback with checkmark)
- Updated thread handler to pass board data for breadcrumb context
- Server-side validation for password confirmation field
- Display error message if passwords don't match
- Complements client-side validation added in previous commit
- A new `files` table to store metadata about uploaded files, including original name and hash.
- The `users` table is updated to reference a `pfp_file_id` from the new `files` table, removing the insecure `pfp_url` field.
- A new `/file` endpoint and handler (`handlers/file.go`) are created to serve files securely based on their ID, preventing direct file system access.
- Profile editing (`handlers/profile_edit.go` and `templates/pages/profile_edit.html`) is updated to handle file uploads instead of URL inputs.
- The chat feature (`models/chat.go` and `templates/pages/chat.html`) is updated to work with the new file ID system, ensuring avatars are displayed correctly.
Should also fix#68.