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>

dist/vendor/composer/installed.php

@@ -3,7 +3,7 @@
         'name' => 'boha/website',
         'pretty_version' => 'dev-master',
         'version' => 'dev-master',
-        'reference' => '308941449e1b5f1ec6752c297d286e6633c11fed',
+        'reference' => '9e3c95e5764f4ec5167c09b9f9cf05a58891a0aa',
         'type' => 'project',
         'install_path' => __DIR__ . '/../../',
         'aliases' => array(),
@@ -13,7 +13,7 @@
         'boha/website' => array(
             'pretty_version' => 'dev-master',
             'version' => 'dev-master',
-            'reference' => '308941449e1b5f1ec6752c297d286e6633c11fed',
+            'reference' => '9e3c95e5764f4ec5167c09b9f9cf05a58891a0aa',
             'type' => 'project',
             'install_path' => __DIR__ . '/../../',
             'aliases' => array(),