v0.5.0

Changed

• The drf-mcp bridge now rides drf-mcp's public in-process surface instead of
  importing handler internals. DrfMcpToolset lists tools via
  MCPServer.list_tools and executes them via MCPServer.acall_tool (drf-mcp's
  transport-complete in-process methods), passing the Django request +
  request.user so the call context is built inside drf-mcp. Behaviour is
  unchanged — the same merged inputSchema, serializer validation, permissions,
  and error mapping as before — but the bridge no longer reaches into
  handle_tools_list / handle_tools_call_async / MCPCallContext. Requires
  djangorestframework-mcp-server >= 0.9 (the pin is now >=0.9,<0.10).