feat: Story 9 - Remove scroll bars for cleaner UI

Implemented Story 9: Hidden Scroll Bars
- Added CSS to hide scroll bars globally while maintaining functionality
- Used scrollbar-width: none for Firefox
- Used ::-webkit-scrollbar { display: none; } for Chrome/Safari/Edge
- Set overflow-x: hidden to prevent unwanted horizontal scrolling
- Maintained full scroll functionality (mouse wheel, trackpad, keyboard)

Updated Specs
- Added Scroll Bar Styling section to UI_UX.md
- Documented cross-browser compatibility requirements
- Specified areas affected and implementation approach

Bug Fixes
- Fixed biome linting issues in App.tsx (import organization, button type)
- Applied biome formatter for consistent code style

.living_spec/specs/functional/UI_UX.md

@@ -53,3 +53,32 @@ Tool outputs should be rendered in a collapsible component that is **closed by d
 *   Or implement custom collapsible component with proper ARIA attributes
 *   Tool outputs should be visually distinct (border, background color, or badge)
 *   Multiple tool calls in sequence should each be independently collapsible
+
+## Scroll Bar Styling
+
+### Problem
+Visible scroll bars create visual clutter and make the interface feel less polished. Standard browser scroll bars can be distracting and break the clean aesthetic of the dark theme.
+
+### Solution: Hidden Scroll Bars with Maintained Functionality
+Scroll bars should be hidden while maintaining full scroll functionality.
+
+### Requirements
+
+1. **Visual:** Scroll bars should not be visible to the user
+2. **Functionality:** Scrolling must still work perfectly:
+   - Mouse wheel scrolling
+   - Trackpad scrolling
+   - Keyboard navigation (arrow keys, page up/down)
+   - Auto-scroll to bottom for new messages
+3. **Cross-browser:** Solution must work on Chrome, Firefox, and Safari
+4. **Areas affected:**
+   - Main chat message area (vertical scroll)
+   - Tool output content (both vertical and horizontal)
+   - Any other scrollable containers
+
+### Implementation Notes
+*   Use CSS `scrollbar-width: none` for Firefox
+*   Use `::-webkit-scrollbar { display: none; }` for Chrome/Safari/Edge
+*   Maintain `overflow: auto` or `overflow-y: scroll` to preserve scroll functionality
+*   Ensure `overflow-x: hidden` where horizontal scroll is not needed
+*   Test with very long messages and large tool outputs to ensure no layout breaking

.living_spec/stories/09_remove_scroll_bars.md

@@ -1,3 +0,0 @@
-there is a scroll bar on the right that looks gross. also a horizontal scroll bar that should come out
-
-story needs to be worked through

.living_spec/stories/archive/09_remove_scroll_bars.md

@@ -0,0 +1,27 @@
+# Story: Remove Unnecessary Scroll Bars
+
+## User Story
+**As a** User
+**I want** the UI to have clean, minimal scrolling without visible scroll bars
+**So that** the interface looks polished and doesn't have distracting visual clutter.
+
+## Acceptance Criteria
+*   [x] Remove or hide the vertical scroll bar on the right side of the chat area
+*   [x] Remove or hide any horizontal scroll bars that appear
+*   [x] Maintain scrolling functionality (content should still be scrollable, just without visible bars)
+*   [x] Consider using overlay scroll bars or auto-hiding scroll bars for better aesthetics
+*   [x] Ensure the solution works across different browsers (Chrome, Firefox, Safari)
+*   [x] Verify that long messages and tool outputs still scroll properly
+
+## Out of Scope
+*   Custom scroll bar designs with fancy styling
+*   Touch/gesture scrolling improvements for mobile (desktop focus for now)
+
+## Implementation Notes
+*   Use CSS `scrollbar-width: none` for Firefox
+*   Use `::-webkit-scrollbar { display: none; }` for Chrome/Safari
+*   Ensure `overflow: auto` or `overflow-y: scroll` is still applied to maintain scroll functionality
+*   Test with long tool outputs and chat histories to ensure no layout breaking
+
+## Related Functional Specs
+*   Functional Spec: UI/UX