feat: integrate ProjectFileManager into project detail page

Replace the file management placeholder with the actual ProjectFileManager
component, providing projectId, projectNumber, hasPermission, and hasNasFolder
props from the existing page state.

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

src/admin/pages/ProjectDetail.tsx

@@ -8,6 +8,7 @@ import Forbidden from '../components/Forbidden'
 import ConfirmModal from '../components/ConfirmModal'
 import FormField from '../components/FormField'
 import AdminDatePicker from '../components/AdminDatePicker'
+import ProjectFileManager from '../components/ProjectFileManager'
 import apiFetch from '../utils/api'
 
 const API_BASE = '/api/admin'
@@ -559,20 +560,18 @@ export default function ProjectDetail() {
         </div>
       </motion.div>
 
-      {/* Files placeholder - ProjectFileManager not yet migrated */}
+      {/* Project File Manager */}
       <motion.div
-        className="admin-card"
-        style={{ marginBottom: '1rem' }}
         initial={{ opacity: 0, y: 12 }}
         animate={{ opacity: 1, y: 0 }}
         transition={{ duration: 0.25, delay: 0.12 }}
       >
-        <div className="admin-card-body">
-          <h3 className="admin-card-title">Soubory</h3>
-          <p style={{ color: 'var(--text-tertiary)', fontSize: '0.875rem' }}>
-            Správa souborů projektu bude dostupná v příští verzi.
-          </p>
-        </div>
+        <ProjectFileManager
+          projectId={project.id}
+          projectNumber={project.project_number}
+          hasPermission={hasPermission}
+          hasNasFolder={project.has_nas_folder ?? false}
+        />
       </motion.div>
 
       {/* Links */}