MCP Tool Details default dashboard widgets filter on span.name instead of span.op, causing "No Data"

### Environment

SaaS (https://sentry.io/)

### Steps to Reproduce

1. Set up MCP monitoring with `@sentry/node` following the official docs: https://docs.sentry.io/ai/monitoring/mcp/getting-started/
2. Send some MCP traffic (tool calls, etc.)
3. Open the default **MCP Tool Details** dashboard
4. All widgets show "No Data"

- SDK: `@sentry/node` v10.51.0
- Runtime: Node.js v22
- MCP SDK: `@modelcontextprotocol/sdk`

### Expected Result

Default dashboard widgets should display MCP tool data out of the box.

### Actual Result

Widgets filter on `span.name:mcp.server` which never matches because `span.name` is set to the method description (e.g., `tools/call list_plans`), not `mcp.server`.

### Product Area

Dashboards

### Link

https://....sentry.io/dashboard/3202142/?project=5947627

### DSN

_No response_

### Version

_No response_