Agentic software factory Part 11: local:gate, per-file coverage in CI, pre-push-gate skill

[cliffhall]

Part of the agentic software factory tracker #4858, Wave 4. Proposed as S10 in docs/agent-guidance-inception.md (PR #4861) §9, from #4859.

Depends on

After Part 3 (skills infrastructure, for verify:skills:cli), Part 4 (TS gate), Part 5 (Python gate), #4854 and #4855.

Scope

• A root npm run local:gate, run under the Inspector's gate-lease.mjs so concurrent sessions queue. It chains:
  • the TS validate and the Python validate
  • verify:skills:cli
  • per-file coverage for both languages, from 2026-07-28 Spec Refactor Part 1: TypeScript servers: extensive unit tests + per-file 90% coverage gate #4854 and 2026-07-28 Spec Refactor Part 2: Python servers: extensive unit tests + per-file 90% coverage gate #4855
  • a thin boot smoke for each server over each transport it implements: stdio for all seven, plus SSE and Streamable HTTP for everything
  • Adopt MCP interface-diff CI for the everything server (decide on PR #3260) #4860's interface diff, once that lands
• CI runs coverage as a parallel job, as the Inspector now does (inspector#2159). This reverses the "coverage stays local" note in 2026-07-28 Spec Refactor Part 1: TypeScript servers: extensive unit tests + per-file 90% coverage gate #4854 and 2026-07-28 Spec Refactor Part 2: Python servers: extensive unit tests + per-file 90% coverage gate #4855.
• timeout-minutes on every CI job; none declare one today.
• Assert that no tests retry.
• Port scripts/lib/workflow-gate.mjs and its tests, so no workflow can invoke a local:* script and local:gate stays exactly the lease wrapper.
• Add docs/quality-gate.md and the pre-push-gate skill.
• Add the AGENTS.md rules: the mandatory pre-push gate, and the per-file ≥ 90 coverage rule, with a reason on every ignore or pragma. For TypeScript that is all four Vitest dimensions (lines, statements, functions, branches). For Python it is per-file lines and branches, the dimensions coverage.py measures; it has no native function dimension. The coverage rule is the carry-over task from 2026-07-28 Spec Refactor Part 1: TypeScript servers: extensive unit tests + per-file 90% coverage gate #4854 and 2026-07-28 Spec Refactor Part 2: Python servers: extensive unit tests + per-file 90% coverage gate #4855.

Acceptance criteria

• npm run local:gate runs every check CI runs.
• A PR that drops any file below 90 fails CI.
• Concurrent gates queue.
• The skill carries eval cases that pass the threshold.
• If this is the first skill-adding PR to merge, remove Part 3's empty-skills bootstrap allowance from verify:skills.

Branch

Targets v2/main. Closes #N won't auto-close an issue on a non-default branch, so close this one by hand on merge and move the card to Done.