chore: replace Unicode/emoji icons with Lucide React

Adds lucide-react and replaces all HTML entity and emoji icons across
the UI with proper SVG icon components. Tree-shaken — only imported
icons are bundled.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

ui/src/pages/Admin/AppConfigPage.tsx

@@ -1,5 +1,6 @@
 import { useState, useMemo, useEffect } from 'react';
 import { useNavigate, useSearchParams } from 'react-router';
+import { Pencil, X } from 'lucide-react';
 import {
   DataTable, Badge, MonoText, DetailPanel, SectionHeader, Button, Toggle, Spinner, useToast,
 } from '@cameleer/design-system';
@@ -197,7 +198,7 @@ function AppConfigDetail({ appId, onClose }: { appId: string; onClose: () => voi
     ...(editing ? [{
       key: '_remove' as const, header: '', width: '36px',
       render: (_v: unknown, row: TracedTapRow) => row.captureMode === null ? null : (
-        <button className={styles.removeBtn} title="Remove" onClick={() => updateTracedProcessor(row.processorId, 'REMOVE')}>&times;</button>
+        <button className={styles.removeBtn} title="Remove" onClick={() => updateTracedProcessor(row.processorId, 'REMOVE')}><X size={14} /></button>
       ),
     }] : []),
   ], [editing, processorToRoute]);
@@ -233,7 +234,7 @@ function AppConfigDetail({ appId, onClose }: { appId: string; onClose: () => voi
             </Button>
           </div>
         ) : (
-          <button className={styles.editBtn} onClick={startEditing} title="Edit configuration">&#x270E;</button>
+          <button className={styles.editBtn} onClick={startEditing} title="Edit configuration"><Pencil size={14} /></button>
         )}
       </div>