Add Play All, home navigation, and UI improvements

- Add Play All button with M3U playlist generation (local temp file with absolute paths)
- Replace folder combobox with root folder cards and home icon breadcrumb
- Fix compact grid card sizing (64x64 thumbnails, align-items: start)
- Add loading spinner when browsing folders
- Cache browse items to avoid re-fetching on view mode switch
- Remove unused browser-controls CSS
- Add localization keys for Play All and Home (en/ru)

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

media_server/routes/browser.py

@@ -2,6 +2,7 @@
 
 import asyncio
 import logging
+import tempfile
 from pathlib import Path
 from typing import Optional
 from urllib.parse import unquote
@@ -48,6 +49,13 @@ class PlayRequest(BaseModel):
     path: str = Field(..., description="Full path to the media file")
 
 
+class PlayFolderRequest(BaseModel):
+    """Request model for playing all media files in a folder."""
+
+    folder_id: str = Field(..., description="Media folder ID")
+    path: str = Field(default="", description="Path relative to folder root")
+
+
 # Folder Management Endpoints
 @router.get("/folders")
 async def list_folders(_: str = Depends(verify_token)):
@@ -423,6 +431,89 @@ async def play_file(
         raise HTTPException(status_code=500, detail="Failed to play file")
 
 
+# Play Folder Endpoint (M3U playlist)
+@router.post("/play-folder")
+async def play_folder(
+    request: PlayFolderRequest,
+    _: str = Depends(verify_token),
+):
+    """Play all media files in a folder by generating an M3U playlist.
+
+    Args:
+        request: Play folder request with folder_id and path.
+
+    Returns:
+        Success message with file count.
+
+    Raises:
+        HTTPException: If folder not found or playback fails.
+    """
+    try:
+        decoded_path = unquote(request.path)
+        full_path = BrowserService.validate_path(request.folder_id, decoded_path)
+
+        if not full_path.is_dir():
+            raise HTTPException(status_code=400, detail="Path is not a directory")
+
+        # Collect all media files sorted by name
+        media_files = sorted(
+            [f for f in full_path.iterdir() if f.is_file() and BrowserService.is_media_file(f)],
+            key=lambda f: f.name.lower(),
+        )
+
+        if not media_files:
+            raise HTTPException(status_code=404, detail="No media files found in this folder")
+
+        # Generate M3U playlist with absolute paths and EXTINF entries
+        # Written to local temp dir to avoid extra SMB file handle on network shares
+        # Uses utf-8-sig (BOM) so players detect encoding properly
+        m3u_content = "#EXTM3U\r\n"
+        for f in media_files:
+            m3u_content += f"#EXTINF:-1,{f.stem}\r\n"
+            m3u_content += f"{f}\r\n"
+
+        playlist_path = Path(tempfile.gettempdir()) / ".media_server_playlist.m3u"
+        playlist_path.write_text(m3u_content, encoding="utf-8-sig")
+
+        # Open playlist with default player
+        controller = get_media_controller()
+        success = await controller.open_file(playlist_path)
+
+        if not success:
+            raise HTTPException(status_code=500, detail="Failed to open playlist")
+
+        # Wait for media player to start
+        await asyncio.sleep(1.5)
+
+        # Broadcast status update
+        try:
+            status = await controller.get_status()
+            status_dict = status.model_dump()
+            await ws_manager.broadcast({
+                "type": "status",
+                "data": status_dict
+            })
+            logger.info(f"Broadcasted status after opening playlist with {len(media_files)} files")
+        except Exception as e:
+            logger.warning(f"Failed to broadcast status after opening playlist: {e}")
+
+        return {
+            "success": True,
+            "message": f"Playing {len(media_files)} files",
+            "count": len(media_files),
+        }
+
+    except HTTPException:
+        raise
+    except ValueError as e:
+        raise HTTPException(status_code=400, detail=str(e))
+    except FileNotFoundError as e:
+        raise HTTPException(status_code=404, detail=str(e))
+    except Exception as e:
+        logger.error(f"Error playing folder: {e}")
+        raise HTTPException(status_code=500, detail="Failed to play folder")
+
+
 # Download Endpoint
 @router.get("/download")
 async def download_file(