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/app.ts

@@ -3,11 +3,12 @@ import { CommonModule } from '@angular/common';
 import { RouterOutlet, RouterLink, RouterLinkActive } from '@angular/router';
 import { provideHttpClient } from '@angular/common/http';
 import { ArtifactService } from './services/artifact';
+import { LucideAngularModule, Database, Upload, Search } from 'lucide-angular';
 
 @Component({
   selector: 'app-root',
   standalone: true,
-  imports: [CommonModule, RouterOutlet, RouterLink, RouterLinkActive],
+  imports: [CommonModule, RouterOutlet, RouterLink, RouterLinkActive, LucideAngularModule],
   template: `
     <div class="container">
       <header>
@@ -20,13 +21,13 @@ import { ArtifactService } from './services/artifact';
 
       <nav class="tabs">
         <a routerLink="/artifacts" routerLinkActive="active" class="tab-button">
-          📦 Artifacts
+          <lucide-icon [img]="Database" [size]="16"></lucide-icon> Artifacts
         </a>
         <a routerLink="/upload" routerLinkActive="active" class="tab-button">
-          📤 Upload
+          <lucide-icon [img]="Upload" [size]="16"></lucide-icon> Upload
         </a>
         <a routerLink="/query" routerLinkActive="active" class="tab-button">
-          🔍 Query
+          <lucide-icon [img]="Search" [size]="16"></lucide-icon> Query
         </a>
       </nav>
 
@@ -38,6 +39,9 @@ import { ArtifactService } from './services/artifact';
 export class AppComponent implements OnInit {
   deploymentMode: string = '';
   storageBackend: string = '';
+  readonly Database = Database;
+  readonly Upload = Upload;
+  readonly Search = Search;
 
   constructor(private artifactService: ArtifactService) {}