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/app.py

@@ -1072,7 +1072,11 @@ def get_app(transport: str = "sse", enabled_apps: list[str] | None = None):
         # ADR-016: Use Smithery lifespan for stateless mode, BasicAuth otherwise
         if deployment_mode == DeploymentMode.SMITHERY_STATELESS:
             logger.info("Configuring MCP server for Smithery stateless mode")
-            mcp = FastMCP("Nextcloud MCP", lifespan=app_lifespan_smithery)
+            # json_response=True returns plain JSON-RPC instead of SSE format,
+            # required for Smithery scanner compatibility
+            mcp = FastMCP(
+                "Nextcloud MCP", lifespan=app_lifespan_smithery, json_response=True
+            )
         else:
             logger.info("Configuring MCP server for BasicAuth mode")
             mcp = FastMCP("Nextcloud MCP", lifespan=app_lifespan_basic)