fix(scripts): opt fixture capture out of Node's Happy-Eyeballs connect

[JSONbored]

Summary

• scripts/capture-fixtures.mjs's DNS-pinning lookup callback (SSRF/rebinding guard) only supports the old single-address dns.lookup callback signature.
• Node's Happy-Eyeballs dual-stack connect path (autoSelectFamily, default-on since Node 20+) calls custom lookup callbacks with { all: true } and expects an array back -- this callback returns a scalar, so every request threw TypeError [ERR_INVALID_IP_ADDRESS]: Invalid IP address: undefined.
• Result in production: 0/598 fixtures captured, capture-failed on 100% of candidates, which also broke get_fixture/get_api_schema downstream (both REST and MCP).
• The sibling safeFetch helper in scripts/lib.mjs (used by snapshot-openapi.mjs and others) was unaffected -- it goes through undici's Agent/dispatcher, not node:http's raw lookup option, and its createPinnedLookup already handles both callback shapes.
• Fix: autoSelectFamily: false on the request options -- this pinned single-address lookup never needed the multi-attempt path.

Found during a full data-source audit following D1 retirement (unrelated to D1 -- pure Node runtime-behavior regression).

Test plan

• Reproduced the exact TypeError locally against a known-healthy target (apex.api.macrocosmos.ai)
• Confirmed autoSelectFamily: false resolves it against the same target
• node scripts/capture-fixtures.mjs --dry-run: went from 0/590 (0%) to ~420/590 (~72%) captured; all remaining failures are legitimate (429 rate limits, non-JSON content-type, real 404/422/502/503, oversized bodies, genuine timeouts) -- zero TypeErrors remain
• npx eslint / npx prettier --check clean

[superagent-security]

Superagent didn't find any vulnerabilities or security issues in this PR.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 97.85%. Comparing base (632d986) to head (4232ec0).
⚠️ Report is 1 commits behind head on main.
✅ All tests successful. No failed tests found.

Additional details and impacted files

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  Files         174      174           
  Lines       22196    22196           
  Branches     8798     8798           
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  Hits        21721    21721           
  Misses         81       81           
  Partials      394      394           

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