Rewrites chat.css to use centralized CSS variables from app.css instead
of maintaining its own theme definitions. Moves all theme variables
(colors, spacing, shadows, transitions) to app.css as the single source
of truth. Improves chat UI consistency, adds better connection status
indicators, and enhances responsive design.
- Implement singleton pattern for chatApp to prevent multiple instances
- Gate initialization with isInitialized to skip repeated init calls
- Add guards for auth and WebSocket connections to avoid overlaps
- Filter non-message payloads and only render content messages
- Improve scroll-to-bottom button visibility and interaction
- Update scrollbar styling, including dark theme rules
- Removed stray `o` character after `pendingContextChange` declaration to fix a syntax error in `chat.js`.
- Added safety check before calling `focus()` on the message input element.
- Implemented `preloadChatCSS()` to preload chat styles and prevent flash‑of‑unstyled‑content.
- Added GSAP fade‑in animation when switching sections for smoother visual transition.
- Ensured input field is auto‑focused after a section loads.
- Changed the default initial section from `drive` to `chat` to align with new default behavior.
- Removed the unused `serve_html` handler and its import.
- Added a fallback static file service that serves `index.html` for any unmatched path, enabling proper SPA routing.
- Reordered service registration to place the fallback before the explicit index route.
- Cleaned up redundant blank lines and imports in `mod.rs`.
**Client-side (chat.js) updates**
- Renamed the message input variable from `input` to `messageInputEl` for clarity.
- Introduced `pendingContextChange` placeholder for future context handling.
- Switched initialization event from `document 'ready'` to `window 'load'`.
- Updated DOM element assignments and focus calls to use the new variable name.
- Removed unused sidebar auto‑close logic and obsolete session loading functions (`loadSessions`, `loadSessionHistory`).
- Minor refactoring and comment adjustments to improve readability and eliminate dead code.
- Add `*.log` to `.gitignore` to exclude log files from version control.
- Change `auth_handler` to `pub` in `src/auth/mod.rs` to make the endpoint publicly accessible.
- Remove unused `bot_index` import and route; replace direct service registration with `web_server::configure_app` in `src/main.rs`.
- Refactor `src/web_server/mod.rs`:
- Remove the `bot_index` handler.
- Introduce `serve_html` helper for loading HTML pages.
- Simplify static file serving by configuring separate routes for JS and CSS assets.
- Centralize all route and static file configuration in `configure_app`.
- Clean up related imports and improve error handling for missing pages.
- Added a new "Chat" link in the desktop navigation bar with appropriate click handling and active state styling.
- Updated the layout configuration to include the Chat section, mapping it to `chat/chat.html`.
- Enables users to switch to the Chat interface directly from the main navigation.
