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/package.json

@@ -29,6 +29,7 @@
     "@angular/forms": "^19.0.0",
     "@angular/platform-browser": "^19.0.0",
     "@angular/router": "^19.0.0",
+    "lucide-angular": "^0.545.0",
     "rxjs": "~7.8.0",
     "tslib": "^2.3.0",
     "zone.js": "~0.15.0"
@@ -46,4 +47,4 @@
     "karma-jasmine-html-reporter": "~2.1.0",
     "typescript": "~5.8.0"
   }
-}
+}