feat: filemanager s NAS pro projekty

- NasFileManager.php - filesystem helper (browse, upload, download, delete, rename, mkdir)
- project-files.php API - CRUD operace nad soubory projektu
- ProjectFileManager.jsx - React komponenta v detailu projektu
- Automaticke vytvoreni slozky pri vytvoreni projektu (rucne i z objednavky)
- Prejmenovani slozky pri zmene nazvu projektu
- Checkbox "Smazat i soubory na disku" pri mazani projektu/objednavky
- Path traversal ochrana, MIME validace, blocklist nebezpecnych typu
- Bily spinner v primary tlacitkach, ConfirmModal message jako div
- Case-insensitive rename fix pro Windows filesystem

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

api/admin/handlers/projects-handlers.php

@@ -121,6 +121,10 @@ function handleCreateProject(PDO $pdo): void
             'customer_id' => $customerId,
         ], "Ručně vytvořen projekt '$projectNumber'");
 
+        // Vytvorit slozku na NAS
+        $fm = new NasFileManager();
+        $fm->createProjectFolder($projectNumber, $name);
+
         successResponse([
             'project_id' => $projectId,
             'project_number' => $projectNumber,
@@ -134,6 +138,9 @@ function handleCreateProject(PDO $pdo): void
 
 function handleDeleteProject(PDO $pdo, int $id): void
 {
+    $input = getJsonInput();
+    $deleteFiles = (bool) ($input['delete_files'] ?? false);
+
     $stmt = $pdo->prepare(
         'SELECT id, project_number, name, order_id, status FROM projects WHERE id = ?'
     );
@@ -161,12 +168,18 @@ function handleDeleteProject(PDO $pdo, int $id): void
 
         $pdo->commit();
 
+        // Smazat slozku na NAS pokud pozadovano
+        if ($deleteFiles) {
+            $fm = new NasFileManager();
+            $fm->deleteProjectFolder($project['project_number']);
+        }
+
         AuditLog::logUpdate(
             'projects_project',
             $id,
             ['status' => $project['status']],
             ['status' => 'deleted'],
-            "Smazán ruční projekt '{$project['project_number']}'"
+            "Smazán ruční projekt '{$project['project_number']}'" . ($deleteFiles ? ' (včetně souborů)' : '')
         );
 
         successResponse(null, 'Projekt byl smazán');
@@ -254,6 +267,10 @@ function handleGetDetail(PDO $pdo, int $id): void
         errorResponse('Projekt nebyl nalezen', 404);
     }
 
+    // Kontrola existence slozky na NAS
+    $fm = new NasFileManager();
+    $project['has_nas_folder'] = $fm->projectFolderExists($project['project_number']);
+
     successResponse($project);
 }
 
@@ -344,6 +361,12 @@ function handleUpdateProject(PDO $pdo, int $id): void
 
         $pdo->commit();
 
+        // Prejmenovani slozky na NAS pokud se zmenil nazev
+        if ($name !== $project['name']) {
+            $fm = new NasFileManager();
+            $fm->renameProjectFolder($project['project_number'], $name);
+        }
+
         AuditLog::logUpdate(
             'projects_project',
             $id,