feat(api): add GET /api/admin/properties endpoint for admin panel

Previously admin.js used public /api/properties endpoint which lacks
admin-specific fields and returns published_only. New endpoint:
- Returns all properties (not just published)
- Supports status/type filtering
- Returns total count for pagination
- Protected by requireAdmin middleware

Fixes: admin properties table loading with full dataset.

src/server/index.ts

@@ -1121,6 +1121,33 @@ app.post('/api/admin/upload', requireAdmin, adminRateLimit, async (c) => {
 })
 
 // ============ ADMIN PROPERTIES ============
+app.get('/api/admin/properties', requireAdmin, (c) => {
+  const status = c.req.query('status') || 'active'
+  const type = c.req.query('type')
+  const limit = parseInt(c.req.query('limit') || '100')
+  const offset = parseInt(c.req.query('offset') || '0')
+
+  let query = 'SELECT * FROM properties WHERE status = ?'
+  const params: any[] = [status]
+
+  if (type) {
+    query += ' AND type = ?'
+    params.push(type)
+  }
+
+  query += ' ORDER BY is_featured DESC, created_at DESC LIMIT ? OFFSET ?'
+  params.push(limit, offset)
+
+  const properties = db.query(query).all(...params)
+  const total = (db.query('SELECT COUNT(*) as count FROM properties WHERE status = ?').get(status) as any)?.count || 0
+
+  return c.json({
+    success: true,
+    data: properties,
+    total
+  })
+})
+
 app.post('/api/admin/properties', requireAdmin, adminRateLimit, async (c) => {
   try {
     const body = await c.req.json()