chore: run the full quality gate and refresh test tooling

[KIM3310]

Summary

• Run npm run verify in both Node 20/22 CI matrix jobs so Biome and typecheck cannot be skipped.
• Update Biome and Vitest/coverage tooling within the current major versions.
• Refresh lockfile resolution and restore native optional-package libc selectors for npm portability.

Validation

• npm ci — PASS — clean lockfile install; 0 audit findings.
• npm run verify — PASS — Biome, typecheck/build, and 260/260 tests.
• npm audit --audit-level=high — PASS — 0 vulnerabilities.

Review notes

• Local validation used Node 22; hosted CI must exercise the unchanged Node 20/22 matrix.
• No package publication or Pages deployment was run.
• This PR is intentionally a draft until hosted CI and security checks complete.

Repository metadata

• Existing topics were preserved and the planned discoverability topics were added separately.

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Branch: chore/upgrade-polish-2026
Commit: 1611f71e20db85d818e51fa63f8e94a09249e712