fix(smithery): Enable JSON response format for scanner compatibility

The Smithery scanner was reporting "0 tools" despite the server returning
valid tool definitions. Root cause: the server was returning SSE-formatted
responses (event: message\ndata: {...}) which the scanner couldn't parse.

Changes:
- Add json_response=True to FastMCP for Smithery stateless mode
- Clean up verbose docstring examples in semantic.py and webdav.py

The MCP spec allows both SSE and plain JSON responses for HTTP transport.
Setting json_response=True returns Content-Type: application/json with
plain JSON-RPC instead of text/event-stream with SSE format.

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

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

nextcloud_mcp_server/server/webdav.py

@@ -64,20 +64,6 @@ def configure_webdav_tools(mcp: FastMCP):
             - Text files are decoded to UTF-8
             - Documents (PDF, DOCX, etc.) are parsed and text is extracted
             - Other binary files are base64 encoded
-
-        Examples:
-            # Read a text file
-            result = await nc_webdav_read_file("Documents/readme.txt")
-            logger.info(result['content'])  # Decoded text content
-
-            # Read a PDF document (automatically parsed)
-            result = await nc_webdav_read_file("Documents/report.pdf")
-            logger.info(result['content'])  # Extracted text from PDF
-            logger.info(result['parsing_metadata'])  # Document parsing info
-
-            # Read a binary file
-            result = await nc_webdav_read_file("Images/photo.jpg")
-            logger.info(result['encoding'])  # 'base64'
         """
         client = await get_client(ctx)
         content, content_type = await client.webdav.read_file(path)