fix(index): paste fills only project files, photo stays webcam-only

- pasted images/files always go to "Файлы проекта", never to the entry photo
- drop the photo paste hint and the capturedName plumbing: the entry photo is
  captured from the camera only (submit still requires it)
- keep paste naming ("Вставка <date>.<ext>") and server-mirrored limits

public/index.html

@@ -113,7 +113,6 @@ nav a:hover{color:var(--text)}
       <div class="photo-btns">
         <button type="button" class="cam" id="openCamBtn">Камера</button>
       </div>
-      <p class="paste-hint" id="photoPasteHint">Ctrl+V — вставить фото из буфера</p>
     </div>
     <div class="files-card">
       <div class="files-head">