feat: Improve MediaAssetCard design and add responsive sidebar footer (#6749)

## Summary
Implements design feedback for the asset panel, improving visual
hierarchy, contrast, and responsiveness based on design tokens update.

## Changes

### 🎨 Design System Updates (style.css)
- **New tokens for MediaAssetCard states:**
  - `--modal-card-background-hovered`: Hover state background
  - `--modal-card-border-highlighted`: Selected state border color
- **Updated tag contrast:**
  - Light mode: `smoke-200` → `smoke-400`
  - Dark mode: `charcoal-200` → `ash-800`
- **Registered tokens in Tailwind** via `@theme inline` for proper class
generation

### 🖼️ MediaAssetCard Improvements
- **Added tooltips** to all interactive buttons:
  - Zoom button: "Inspect"
  - More button: "More options"
  - Output count button: "See more outputs"
- **Fixed tooltip event conflicts** by wrapping buttons in tooltip divs
- **Updated hover/selected states:**
  - Hover: Uses `--modal-card-background-hovered` for subtle highlight
- Selected: Uses `--modal-card-border-highlighted` for border only (no
background)
- **Updated placeholder background** to use
`--modal-card-placeholder-background`
- **Tag styling:** Changed from `variant="light"` to `variant="gray"`
for better contrast

### 📦 SquareChip Component
- **Added `gray` variant** that uses `--modal-card-tag-background` token
- Maintains consistency with design system tokens

### 📱 AssetsSidebarTab Responsive Footer
- **Responsive button display:**
  - Width > 350px: Shows icon + text buttons
  - Width ≤ 350px: Shows icon-only buttons
- **Text alignment:** Left-aligns selection count text in compact mode
- **Uses `useResizeObserver`** for automatic width detection

### 🌐 Internationalization
- Added new i18n keys for tooltips:
  - `mediaAsset.actions.inspect`
  - `mediaAsset.actions.more`
  - `mediaAsset.actions.seeMoreOutputs`

### 🔧 Minor Fixes
- **Media3DTop:** Improved text size and icon color for better visual
hierarchy

## Visual Changes
- **Increased contrast** for asset card tags (more visible in both
themes)
- **Hover state** now provides clear visual feedback
- **Selected state** uses border highlight instead of background fill
- **Sidebar footer** gracefully adapts to narrow widths

## Related
- Addresses feedback from:
https://www.notion.so/comfy-org/Asset-panel-feedback-2aa6d73d3650800baacaf739a49360b3
- Design token updates by @Alex Tov

## Test Plan
- [ ] Verify asset card hover states in both light and dark themes
- [ ] Verify asset card selected states show highlighted border
- [ ] Test tooltips on all MediaAssetCard buttons
- [ ] Resize sidebar to < 350px and verify footer shows icon-only
buttons
- [ ] Resize sidebar to > 350px and verify footer shows icon + text
buttons
- [ ] Verify tag contrast improvement in both themes
- [ ] Test 3D asset placeholder appearance

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-6749-feat-Improve-MediaAssetCard-design-and-add-responsive-sidebar-footer-2b06d73d365081019b90e110df2f1ae8)
by [Unito](https://www.unito.io)

packages/design-system/src/css/style.css

@@ -268,12 +268,13 @@
    --palette-interface-button-hover-surface:  color-mix(in srgb, var(--interface-panel-surface) 82%, var(--contrast-mix-color));
 
    --modal-card-background: var(--secondary-background);
+   --modal-card-background-hovered: var(--secondary-background-hover);
+   --modal-card-border-highlighted: var(--secondary-background-selected);
    --modal-card-button-surface: var(--color-smoke-300);
    --modal-card-placeholder-background: var(--color-smoke-600);
-   --modal-card-tag-background: var(--color-smoke-200);
+   --modal-card-tag-background: var(--color-smoke-400);
    --modal-card-tag-foreground: var(--base-foreground);
    --modal-panel-background: var(--color-white);
-
 }
 
 .dark-theme {
@@ -377,9 +378,11 @@
   --component-node-widget-background-highlighted: var(--color-graphite-400);
 
   --modal-card-background: var(--secondary-background);
+  --modal-card-background-hovered: var(--secondary-background-hover);
+  --modal-card-border-highlighted: var(--color-ash-400);
   --modal-card-button-surface: var(--color-charcoal-300);
   --modal-card-placeholder-background: var(--secondary-background);
-  --modal-card-tag-background: var(--color-charcoal-200);
+  --modal-card-tag-background: var(--color-ash-800);
   --modal-card-tag-foreground: var(--base-foreground);
   --modal-panel-background: var(--color-charcoal-600);
 
@@ -395,12 +398,14 @@
   --color-subscription-button-gradient: var(--subscription-button-gradient);
 
   --color-modal-card-background: var(--modal-card-background);
+  --color-modal-card-background-hovered: var(--modal-card-background-hovered);
+  --color-modal-card-border-highlighted: var(--modal-card-border-highlighted);
   --color-modal-card-button-surface: var(--modal-card-button-surface);
   --color-modal-card-placeholder-background: var(--modal-card-placeholder-background);
   --color-modal-card-tag-background: var(--modal-card-tag-background);
   --color-modal-card-tag-foreground: var(--modal-card-tag-foreground);
   --color-modal-panel-background: var(--modal-panel-background);
-  
+
   --color-dialog-surface: var(--dialog-surface);
   --color-interface-menu-component-surface-hovered: var(
     --interface-menu-component-surface-hovered