fix(dev-1699): bump nanoid to 3.3.18

[spur-vuln-author]

Context

Batched group (ticket_group_key tg:nanoid:pnpm-lock.yaml, 3 advisories) against nanoid, all in pnpm-lock.yaml:

• GHSA-xwg4-73v4-xw9w — nanoid < 3.3.12 (high)
• GHSA-2v37-7h3g-55p8 — nanoid < 3.3.18 (high)
• GHSA-28wg-ghj8-5hjv — nanoid < 3.3.16 (high)

Transitive dependency (not declared in any package.json), resolved via pnpm-lock.yaml. No Dependabot PR exists for any of these, so this PR was constructed directly from the highest first_patched_version across the group (3.3.18).

Test evidence

No Dependabot PR existed; constructed from first_patched_version 3.3.18 (highest across the batch). Added a pnpm.overrides entry and regenerated the lockfile with pnpm install --lockfile-only. Confirmed via lockfile inspection that nanoid now resolves to 3.3.19 (previously 3.3.11/3.3.12), satisfying >= 3.3.18 for all three advisories. Companion-file scan (Dockerfiles, .nvmrc, go.mod, CI workflow YAML, etc. hardcoding 3.3.11) found no hits.

Risk

Low. Lockfile-only transitive dependency bump within the same major version line, resolves all 3 batched advisories at once. Group max severity high; Tier 1 / 90-day SLA.

---

[spur-vuln-reviewer]

Escalating: Gate 3 (diff equivalence) mechanically FAILed. gate3-check.sh: GATE3 FAIL target=nanoid manifest=pnpm-lock.yaml pr_version=? required=3.3.18 alerts=110,111,113 extra_files=1 state=open. Detail: the helper has no extraction rule for ecosystem=npm manifest basename=pnpm-lock.yaml, so it could not extract the new nanoid version from the diff, and flagged package.json as a file outside {manifest, lockfile} (which is actually the expected direct-dependency file for an npm/pnpm version bump). This looks like a tooling gap in gate3-check.sh (no pnpm-lock.yaml parser) rather than a real diff deviation, but per the review contract a mechanical Gate 3 FAIL is never re-derived or second-guessed by the reviewer. Required version per max open Dependabot alert(s) 110,111,113: 3.3.18. Not merged. A human must review this. This reviewer will not act on this PR again. [[spur-vuln-reviewer: escalated diff-mismatch-constructed]]