test: add comprehensive WebDAV integration tests

- Add 8 core WebDAV operation tests covering CRUD operations
- Add complex attachment cleanup test for category changes
- Fix ruff formatting violations in webdav.py and server.py
- Address PR feedback requirements for expanded WebDAV functionality

Tests focus on WebDAV client functionality and run locally with docker-compose.

🤖 Generated with [Claude Code](https://claude.ai/code)

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

nextcloud_mcp_server/server.py

@@ -195,17 +195,17 @@ async def nc_notes_get_attachment(note_id: int, attachment_filename: str):
 @mcp.tool()
 async def nc_webdav_list_directory(ctx: Context, path: str = ""):
     """List files and directories in the specified NextCloud path.
-    
+
     Args:
         path: Directory path to list (empty string for root directory)
-        
+
     Returns:
         List of items with metadata including name, path, is_directory, size, content_type, last_modified
-        
+
     Examples:
         # List root directory
         await nc_webdav_list_directory("")
-        
+
         # List a specific folder
         await nc_webdav_list_directory("Documents/Projects")
     """
@@ -216,26 +216,26 @@ async def nc_webdav_list_directory(ctx: Context, path: str = ""):
 @mcp.tool()
 async def nc_webdav_read_file(path: str, ctx: Context):
     """Read the content of a file from NextCloud.
-    
+
     Args:
         path: Full path to the file to read
-        
+
     Returns:
         Dict with path, content, content_type, size, and encoding (if binary)
         Text files are decoded to UTF-8, binary files are base64 encoded
-        
+
     Examples:
         # Read a text file
         result = await nc_webdav_read_file("Documents/readme.txt")
         print(result['content'])  # Decoded text content
-        
+
         # Read a binary file
         result = await nc_webdav_read_file("Images/photo.jpg")
         print(result['encoding'])  # 'base64'
     """
     client: NextcloudClient = ctx.request_context.lifespan_context.client
     content, content_type = await client.webdav.read_file(path)
-    
+
     # For text files, decode content for easier viewing
     if content_type and content_type.startswith("text/"):
         try:
@@ -244,68 +244,72 @@ async def nc_webdav_read_file(path: str, ctx: Context):
                 "path": path,
                 "content": decoded_content,
                 "content_type": content_type,
-                "size": len(content)
+                "size": len(content),
             }
         except UnicodeDecodeError:
             pass
-    
+
     # For binary files, return metadata and base64 encoded content
     import base64
+
     return {
         "path": path,
         "content": base64.b64encode(content).decode("ascii"),
         "content_type": content_type,
         "size": len(content),
-        "encoding": "base64"
+        "encoding": "base64",
     }
 
 
 @mcp.tool()
-async def nc_webdav_write_file(path: str, content: str, ctx: Context, content_type: str | None = None):
+async def nc_webdav_write_file(
+    path: str, content: str, ctx: Context, content_type: str | None = None
+):
     """Write content to a file in NextCloud.
-    
+
     Args:
         path: Full path where to write the file
         content: File content (text or base64 for binary)
         content_type: MIME type (auto-detected if not provided, use 'type;base64' for binary)
-        
+
     Returns:
         Dict with status_code indicating success
-        
+
     Examples:
         # Write a text file
         await nc_webdav_write_file("Documents/notes.md", "# My Notes\nContent here...")
-        
+
         # Write binary data (base64 encoded)
         await nc_webdav_write_file("files/data.bin", base64_content, "application/octet-stream;base64")
     """
     client: NextcloudClient = ctx.request_context.lifespan_context.client
-    
+
     # Handle base64 encoded content
     if content_type and "base64" in content_type.lower():
         import base64
+
         content_bytes = base64.b64decode(content)
         content_type = content_type.replace(";base64", "")
     else:
         content_bytes = content.encode("utf-8")
-    
+
     return await client.webdav.write_file(path, content_bytes, content_type)
 
 
 @mcp.tool()
 async def nc_webdav_create_directory(path: str, ctx: Context):
     """Create a directory in NextCloud.
-    
+
     Args:
         path: Full path of the directory to create
-        
+
     Returns:
         Dict with status_code (201 for created, 405 if already exists)
-        
+
     Examples:
         # Create a single directory
         await nc_webdav_create_directory("NewProject")
-        
+
         # Create nested directories (parent must exist)
         await nc_webdav_create_directory("Projects/MyApp/docs")
     """
@@ -316,17 +320,17 @@ async def nc_webdav_create_directory(path: str, ctx: Context):
 @mcp.tool()
 async def nc_webdav_delete_resource(path: str, ctx: Context):
     """Delete a file or directory in NextCloud.
-    
+
     Args:
         path: Full path of the file or directory to delete
-        
+
     Returns:
         Dict with status_code indicating result (404 if not found)
-        
+
     Examples:
         # Delete a file
         await nc_webdav_delete_resource("old_document.txt")
-        
+
         # Delete a directory (will delete all contents)
         await nc_webdav_delete_resource("temp_folder")
     """