chore(specgit): refresh delivery harness

[LeXwDeX]

Closes #488

Why

The checked-in generated SpecGit harness conflicts with the installed specgit 1.10.1, so specgit issue is blocked on fresh feature worktrees — preventing independent deliveries for #433 and #435. This refreshes the harness against 1.10.1 while preserving every repository-specific acceptance-workflow specialization documented in AGENTS.md.

What changed

• specgit init --force re-run with 1.10.1 in a clean worktree on this branch.
• spec_git/policy.yaml, the AGENTS.md/CLAUDE.md managed blocks, and .opencode/hooks.json: 1.10.1 output is byte-identical — no commit needed. The curated required_checks (Typecheck, Unit Tests (linux)) are preserved by design (feat(core): release v1.0.23 — built-in /dag-init and /dag-auto ultra-flow commands #310: a no-argument init --force never replaces a working policy). The canonical ids (unit-tests/e2e-tests) stay out of the policy: they are not observable check-run names on the main-line CI matrix, so the acceptance waiter could never see them (b6473cc, re-affirmed by 29e876a).
• .github/workflows/specgit-accept.yml: kept the repository-specialized workflow verbatim —
  • no workflow_dispatch trigger (main-only pull_request),
  • head-ref checkout retained with persist-credentials: false,
  • global npm install -g specgit@^0.5.0 (the template's npm install --no-save specgit@1.10.1 reads this bun workspace's package.json and dies on the catalog: protocol — fix(ci): dev-lineage specgit-accept installs CLI locally and chokes on bun catalog #434/fix(session): cap summary.diffs at 256KB to stop event-loop starvation #459),
  • yaml-free wait step with the proven 40min inline deadline / 45min job timeout. The 1.10.1 template variant imports yaml with no dependency installed in CI and waits only 13min — shorter than the ~28min Unit Tests sibling (6a3f3b2, 8d5bb3d, 43d6915).
• .opencode/hooks/specgit-merge-guard.sh: the only committed change — takes the 1.10.1 improvement, the merge guard now also blocks glab mr merge, not only gh pr merge.
• .husky/_/pre-push: untracked local pre-push guard (untracked model, ignored by husky on next install) — not committed.

Evidence

• specgit doctor --json → status: ok, exit: 0 (git / repo / origin / gh_authenticated / policy "2 required check(s)" all green).
• specgit init --force output confirms: "Preserved the required checks from the existing policy … this run is a version upgrade of the generated assets, not a policy re-birth."
• Post-init git diff reduced to the single merge-guard line; the acceptance workflow was restored byte-for-byte to the pre-init baseline carrying all four documented deviations.
• Guard hook passes sh -n.

Checklist

• No product source changed.
• No unrelated CI touched.
• Policy checks preserved, gate not weakened.
• specgit doctor --json exits 0.