fix(ui): replace ALL emojis with Lucide icons

AddRepoForm.tsx:
- 📦 → Package icon (modal header)
- 🚀 → Plus icon (submit button)
- ✕ → X icon (close button)

SearchPanel.tsx:
- ⚡ → Zap icon (cached badge)
- 🔍 → Search icon (empty state)

DependencyGraph.tsx:
- 💡 → Lightbulb icon (hint text)

Zero emojis remaining in main UI components.
Professional icon system complete.

Author: DevanshuNEU

frontend/src/components/AddRepoForm.tsx

@@ -1,5 +1,6 @@
 import { useState } from 'react'
 import { motion, AnimatePresence } from 'framer-motion'
+import { Package, Plus, X } from 'lucide-react'
 
 interface AddRepoFormProps {
   onAdd: (gitUrl: string, branch: string) => Promise<void>
@@ -53,7 +54,7 @@ export function AddRepoForm({ onAdd, loading }: AddRepoFormProps) {
               <div className="flex items-center justify-between p-6 border-b border-white/5">
                 <div className="flex items-center gap-3">
                   <div className="w-10 h-10 rounded-xl bg-gradient-to-br from-blue-500/20 to-purple-500/20 flex items-center justify-center">
-                    <span className="text-xl">📦</span>
+                    <Package className="w-5 h-5 text-blue-400" />
                   </div>
                   <div>
                     <h3 className="text-lg font-semibold text-white">Add Repository</h3>
@@ -65,7 +66,7 @@ export function AddRepoForm({ onAdd, loading }: AddRepoFormProps) {
                   className="w-8 h-8 flex items-center justify-center rounded-lg text-gray-400 hover:text-white hover:bg-white/10 transition-colors"
                   disabled={loading}
                 >
-                  ✕
+                  <X className="w-4 h-4" />
                 </button>
               </div>
 
@@ -123,7 +124,7 @@ export function AddRepoForm({ onAdd, loading }: AddRepoFormProps) {
                       </>
                     ) : (
                       <>
-                        <span>🚀</span>
+                        <Plus className="w-4 h-4" />
                         <span>Add & Index</span>
                       </>
                     )}

frontend/src/components/DependencyGraph.tsx

@@ -9,6 +9,7 @@ import ReactFlow, {
 } from 'reactflow'
 import type { Node, Edge } from 'reactflow'
 import dagre from 'dagre'
+import { Lightbulb } from 'lucide-react'
 import 'reactflow/dist/style.css'
 import { useDependencyGraph } from '../hooks/useCachedQuery'
 
@@ -357,8 +358,9 @@ export function DependencyGraph({ repoId, apiUrl, apiKey }: DependencyGraphProps
             <span className="text-gray-400">Dependency</span>
           </div>
         </div>
-        <div className="mt-3 pt-3 border-t border-white/5 text-xs text-gray-500">
-          💡 Click any node to highlight its dependencies • Drag to pan • Scroll to zoom
+        <div className="mt-3 pt-3 border-t border-white/5 text-xs text-gray-500 flex items-center gap-2">
+          <Lightbulb className="w-3.5 h-3.5 text-blue-400" />
+          <span>Click any node to highlight its dependencies • Drag to pan • Scroll to zoom</span>
         </div>
       </div>
     </div>

frontend/src/components/SearchPanel.tsx

@@ -1,5 +1,6 @@
 import { useState } from 'react';
 import { toast } from 'sonner';
+import { Zap, Search } from 'lucide-react';
 import { SearchBox, ResultCard } from './search';
 import type { SearchResult } from '../types';
 
@@ -83,7 +84,10 @@ export function SearchPanel({ repoId, apiUrl, apiKey, repoUrl }: SearchPanelProp
             {cached && (
               <>
                 <span className="text-text-muted">•</span>
-                <span className="badge-success">⚡ Cached</span>
+                <span className="badge-success inline-flex items-center gap-1">
+                  <Zap className="w-3 h-3" />
+                  Cached
+                </span>
               </>
             )}
           </div>
@@ -108,7 +112,7 @@ export function SearchPanel({ repoId, apiUrl, apiKey, repoUrl }: SearchPanelProp
       {results.length === 0 && hasSearched && !loading && (
         <div className="card p-16 text-center">
           <div className="w-20 h-20 mx-auto mb-4 rounded-2xl glass flex items-center justify-center">
-            <span className="text-4xl">🔍</span>
+            <Search className="w-10 h-10 text-gray-500" />
           </div>
           <h3 className="text-base font-semibold mb-2 text-text-primary">No results found</h3>
           <p className="text-sm text-text-secondary">