chore(quality): prefer node:path over path across the codebase

[Zaldaryon]

Summary

Second slice of the #107 SonarCloud triage: the S7772 findings, node:path preferred over the bare path specifier for built-in modules. Mechanical, one import line per file, no behavior change; 16 files touched, path covered every occurrence, no other Node built-ins were imported bare anywhere in src/. The test suite already used node:path everywhere, so this brings src/ in line with that existing convention rather than introducing a new one.

Type

• Bug fix
• Feature
• Performance
• Refactor or cleanup
• Tests only
• Docs or build

Checklist

• Targets dev, not main.
• npm run typecheck passes.
• npm run lint:ci passes.
• npm run format:check passes.
• npm run test:coverage passes, coverage at or above the floor in vitest.config.ts.
• npm run build:unpack passes.

Testing

Import-only change, no logic touched. Ran the full gate list: typecheck, lint:ci, format:check, test:coverage (statements 90.52%, branches 87.72%, functions 88.31%, lines 92.15%, all above the configured floor, same suite that already exercises every file changed here), and build:unpack, all green.

Related issues

Refs #107 (leaves the remaining findings, mainly the 66 read-only-props S6759 findings, for a separate slice)

[Pixnop]

Approving. Verified it is purely mechanical: the diff contains nothing but import lines, 16 files, and the suite already used node:path everywhere so this aligns src with the existing convention. Second slice of #107 done.