Simplify WorkspaceSummary card hover UI with opacity fade and single action button (Vibe Kanban) (#2059)

* All changes are complete. Here's a summary of what was changed:

## Summary of Changes

### `WorkspaceSummary.tsx`
1. **Title truncation**: Replaced `truncate` class with CSS mask gradient that fades to transparent (no ellipsis dots)
2. **Simplified hover actions**: Removed pin and archive buttons, keeping only the "more options" (ListIcon) button
3. **Removed sliding animation**: The action button now uses simple opacity transition (`opacity-0 group-hover:opacity-100`) instead of the sliding animation
4. **Removed unused code**: `handleArchive`, `handlePin` functions and `ArchiveIcon` import removed
5. **Removed unused props**: `onArchive` and `onPin` props removed from interface

### `WorkspacesSidebar.tsx`
- Removed `onArchiveWorkspace` and `onPinWorkspace` props from interface and destructuring

### `WorkspacesSidebarContainer.tsx`
- Removed `handleArchiveWorkspace` and `handlePinWorkspace` callbacks
- Removed unused imports (`useCallback`, `useActions`, `Actions`)

All type checks pass. The pin and archive functionality is still accessible through the command bar (more options button).

* Cleanup script changes for workspace 262a1c1d-87ae-40f5-a36d-f43758d18fed

* Done. Changed `ListIcon` to `DotsThreeIcon` with `weight="bold"` for the more options button.

* Done. Changed the icon size from `size-icon-xs` to `size-5` (20px) while keeping the bold weight.

* Done. Added the `ArchiveWorkspace` action to the left side of the navbar in `NavbarActionGroups.left`.

frontend/src/components/ui-new/actions/index.ts

@@ -965,7 +965,7 @@ export type NavbarItem = ActionDefinition | typeof NavbarDivider;
 
 // Navbar action groups define which actions appear in each section
 export const NavbarActionGroups = {
-  left: [Actions.OpenInOldUI] as ActionDefinition[],
+  left: [Actions.ArchiveWorkspace, Actions.OpenInOldUI] as ActionDefinition[],
   right: [
     Actions.ToggleDiffViewMode,
     Actions.ToggleAllDiffs,