context-guard: setup skill (check + zones-seed apply) + evals

[kyle-sexton]

Parent

Source: PLAN Phase A4, topic plugin-audit-port — plan locked at commit 40a64b5c on
feat/plugin-audit-port.

What to build

context-guard setup skill (disable-model-invocation: true, check/apply contract per
PLUGIN-PHILOSOPHY "Setup is explicit and repeatable"):

• check (read-only): jq presence; statusline wiring state — the stale-path detection compares
  the wired path against the currently resolved ${CLAUDE_PLUGIN_ROOT} so exists-but-outdated
  cache paths are caught, not just missing files; snapshot freshness probe for the live session;
  prints the exact operator settings.json statusline edit (wrapped and standalone variants) —
  NEVER writes settings; dotfiles-tracking reminder (surface only, run nothing).
• apply: scoped to the ONE file the plugin owns the schema of — seed/refresh
  ~/.claude/context-guard/zones.json from the shipped defaults on explicit request; idempotent,
  preserves unrecognized keys in an existing file, reports what it wrote. Nothing else — statusline
  wiring stays print-only (owner-approved EXEC-SHAPE decision).
• Setup evals (skills/setup/evals/evals.json) — setup skills are warrantable; the
  rate-limit-guard setup eval is the model.

Acceptance criteria

• /skill-quality:check passes on the setup skill
• validate-evals passes on skills/setup/evals/evals.json
• check never mutates any file; apply touches only ~/.claude/context-guard/zones.json
• Stale-wiring detection flags a wired path differing from resolved ${CLAUDE_PLUGIN_ROOT}
  even when the old file still exists

Blocked by

• Reader-contract slice (native edge).

[kyle-sexton]

[kyle-sexton]

Closed by PR #1241 (squash 7a868728). Evidence: skill-quality gate PASS (0 errors); evals validate structurally against the bundled schema; stale-wiring detection compares the wired path against the resolved ${CLAUDE_PLUGIN_ROOT} (review-hardened: effective-scope resolution across user/project/local, POSIX-escaped sh -c variant for shell-syntax commands, repair-only bare apply + explicit apply reset, jq-absent merge guard, semantic preservation contract). Clean-repo --plugin-dir smoke: check ran end-to-end, all four states correctly classified, operator edit printed.