fix(core): resolve MCP capture policy per operation - #23437

Backport of: #23437

## Differences to the original PR

- `packages/core/src/integrations/mcp-server/transport.ts`: the
no-client fallback in `resolveMcpOptions` is `false` for
`recordInputs`/`recordOutputs`, not `true`. On v10
`resolveDataCollectionOptions` still routes through the `sendDefaultPii`
bridge when `dataCollection` is absent, so the old
`wrapMcpServerWithSentry` code fell back to `false` when no client
existed. Keeping `true` here would start capturing MCP inputs and
outputs on a maintenance branch.
- `packages/core/src/integrations/mcp-server/transport.ts`:
`startInactiveSpan` is imported from `../../tracing` together with
`withActiveSpan`; v10 has no separate `../../tracing/trace` import in
this file.
-
`packages/core/test/lib/integrations/mcp-server/capturePolicy.test.ts`:
the span-config helpers use `sentry.source` instead of
`sentry.segment.name.source`, and the tool config carries a top-level
`op: 'mcp.server'`, matching v10's `buildMcpServerSpanConfig`. The
no-client case asserts that inputs and outputs are omitted, following
the fallback above.
- `dev-packages/e2e-tests/test-applications/node-express/src/app.ts`:
the `dataCollection.genAI` block is not added. On v10 the presence of
any `dataCollection` key switches the resolution base from the
`sendDefaultPii` bridge to the permissive spec defaults, which would
have flipped `userInfo`, `cookies`, `httpHeaders`, `httpBodies` and
`databaseQueryData` on for every other test in this app. Without the
block, `genAI` already resolves to `{ inputs: false, outputs: false }`,
so the new MCP e2e assertions hold unchanged.
-
`dev-packages/e2e-tests/test-applications/cloudflare-mcp-agent/src/index.ts`:
the `genAI` settings are merged into the existing `dataCollection: {
userInfo: true }` object. v10 already sets `dataCollection` in both
`Sentry.init` calls, so the original patch would have produced a
duplicate key and silently dropped `userInfo: true`.

Co-authored-by: Miguel Betegón <[email protected]>