ci(codeowners): un-trap required checks, auto-render, generate owner tables (#142)

The CODEOWNERS required checks blocked every PR — the real root cause was a
name mismatch, compounded by a path filter:

- branch-protection.json required the contexts `CODEOWNERS / drift` and
  `CODEOWNERS / noedit` (the GitHub UI "workflow / job-id" display form), but
  the jobs report check-run names from their `name:` fields — "CODEOWNERS
  matches source" / "CODEOWNERS not hand-edited". The required contexts
  therefore never matched any reported check and sat permanently pending.
- The workflow was also path-filtered to CODEOWNERS files, so it didn't even
  run for most PRs.

Net effect: with both required checks unsatisfiable, every PR could only land
via admin override (e.g. #140).

Fixes:
- A: drop the `paths:` filter so the workflow runs on every PR and both
  required contexts always report.
- name fix: point branch-protection.json at the actual job names verbatim, and
  add a doc note that the contexts must equal the job `name:` values.
- B: the `drift` job now re-renders and, on same-repo PRs, auto-commits the
  regenerated artifacts back to the branch (mirrors the openapi.json job in
  ci.yml); forks / manual runs strict-check instead. Contributors no longer
  run the script by hand.
- D: render-codeowners.py also generates a "who owns what" path->owners +
  roles table spliced into docs/dev/codeowners.md between markers, so the
  human-readable view never drifts. Idempotent; CODEOWNERS output unchanged.
- docs: correct the stale `enforce_admins: true` line (JSON and live are
  false).

NOTE: the branch-protection.json change only takes effect after an admin runs
`./scripts/apply-branch-protection.sh` (deliberate manual step, per
docs/dev/branch-protection.md). Until then `main` still requires the old
mismatched contexts, so this PR itself needs an admin-override merge — the last
one that should be necessary.

Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

docs/dev/branch-protection.md

@@ -8,7 +8,7 @@ This page explains what the policy says and how to change it.
 
 | Setting | Value | Why |
 |---|---|---|
-| **Required status checks (strict)** | `Classify Changes`, `Check AGENTS.md Links`, `Test Workspace`, `Test omnigraph-server --features aws`, `CODEOWNERS / drift`, `CODEOWNERS / noedit` | Every PR must pass workspace tests, AGENTS.md link integrity, and the CODEOWNERS hygiene checks. `strict: true` requires the branch to be up-to-date with `main` before merge. |
+| **Required status checks (strict)** | `Classify Changes`, `Check AGENTS.md Links`, `Test Workspace`, `Test omnigraph-server --features aws`, `CODEOWNERS matches source`, `CODEOWNERS not hand-edited` | Every PR must pass workspace tests, AGENTS.md link integrity, and the CODEOWNERS hygiene checks. The two CODEOWNERS contexts must equal the job `name:` values in `.github/workflows/codeowners.yml` **verbatim** — a context naming a job that never reports (the old `CODEOWNERS / drift` used the job *id*, and the job was path-filtered) leaves every PR permanently pending and forces admin overrides. `strict: true` requires the branch to be up-to-date with `main` before merge. |
 | **Required approving reviews** | `1` | At least one reviewer. With a 2-person team, going higher would block all merges when one person is unavailable. |
 | **Require code-owner reviews** | `true` | The reviewer must be a code owner per `.github/CODEOWNERS`. This is what makes the codeowners chassis enforced. |
 | **Dismiss stale reviews on new commits** | `true` | A push after approval invalidates the prior review. Prevents the "approve, then sneak in unreviewed changes" pattern. |
@@ -16,7 +16,7 @@ This page explains what the policy says and how to change it.
 | **Disallow force pushes** | `true` | No history rewrites on `main`. |
 | **Disallow branch deletions** | `true` | `main` cannot be deleted. |
 | **Required conversation resolution** | `true` | All review comment threads must be resolved before merge. |
-| **Enforce on admins** | `true` | Even repository admins go through the gates. The point is no bypasses. |
+| **Enforce on admins** | `false` | Admins can override the gates (`enforce_admins: false` in the JSON). This is the intended escape hatch for the 2-person team; tightening to `true` is tracked under hardening below. |
 | **Required signed commits** | not yet | Not enabled. Would lock out maintainers until everyone enrolls GPG/SSH commit signing. Tracked as a follow-up. |
 
 ## How to apply