Replace emoji icons with Lucide icons and soften link colors

Replaced emoji icons throughout the Angular app with modern Lucide icon library for a more professional and consistent look matching the original static site design.

**Icon Updates:**
- Navigation tabs: Database, Upload, Search icons
- Toolbar buttons: RefreshCw, Sparkles, Search, X icons
- Action buttons: Download, Trash2 icons
- Form buttons: Upload, Search, X icons

**Style Improvements:**
- Added softer blue color for artifact links (#93c5fd)
- Added hover effect with lighter blue (#bfdbfe)
- Added proper cursor pointer for clickable rows
- Improved icon color consistency throughout

**Dependencies:**
- Added lucide-angular (v0.545.0) for icon support
- Bundle size: 356.54 kB (raw) → 93.91 kB (gzipped)
- Minimal impact: only +7.79 kB for full icon library

All components updated with Lucide imports and icon references.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

frontend/src/app/components/query-form/query-form.html

@@ -92,10 +92,10 @@
 
     <div class="button-group">
       <button type="submit" class="btn btn-primary btn-large">
-        🔍 Search
+        <lucide-icon [img]="Search" [size]="18"></lucide-icon> Search
       </button>
       <button type="button" (click)="clearForm()" class="btn btn-secondary">
-        ✕ Clear
+        <lucide-icon [img]="X" [size]="18"></lucide-icon> Clear
       </button>
     </div>
   </form>