chore: move committed-generated-artifact freshness checks to lint:ci (#2000)

gsd-test's build leg runs the full 'npm run build' (which regenerates
capability-registry.cjs, loop-host-contract.cjs, package-identity.cjs, etc.),
so committed-freshness guards that lived in the unit suite were masked there:
gsd-test passed a stale-commit that CI's shard-1/3 test then red-flagged
(caught live on PR #1998). The mandated pre-push gate was green on a commit
CI correctly flagged.

Move the committed-state --check guards into a new 'lint:generated-sync'
script wired into lint:ci (the single orchestrated entry point the lint-tests
CI job already runs on a build:lib-only tree, so the committed artifacts are
checked without regeneration). gsd-test no longer contains these guards, so
it can no longer mask them.

- package.json: add lint:generated-sync (7 generators --check); wire into lint:ci.
- generate-package-identity.cjs: add --check mode (was the only generator
  without it); no-arg behaviour unchanged (still writes, as build expects).
- Remove the committed-freshness guards from the unit suite, keeping all
  behavioral/structural tests:
    - capability-registry.test.cjs: drop the --check describe.
    - loop-host-contract.test.cjs: drop the committed-file staleness test
      (keep the normalizeLineEndings unit test).
    - capability-matrix-sync.test.cjs: drop --check + byte-for-byte (keep the
      architectural content invariants: every cap appears, security ship:pre).
    - issue-844-manifest-version-sync.test.cjs: drop describe D (--check).
    - issue-498-package-identity.test.cjs: drop the drift-check test (keep
      behavioral module-export tests); drop the now-unused render import and
      its allow-test-rule exemption (allowlist ratcheted 175 -> 174).

package.json

@@ -97,7 +97,7 @@
     "pretest:coverage": "npm run build:lib && npm run lint:skill-deps",
     "lint": "eslint . --cache --cache-location node_modules/.cache/eslint/",
     "lint:fix": "eslint . --fix",
-    "lint:ci": "npm run lint && npm run lint:skill-deps && node scripts/lint-test-file-count.cjs && node scripts/lint-command-contract.cjs && node scripts/lint-pr-check-project-dir.cjs && npm run lint:legacy-name && node scripts/lint-regression-test-names.cjs && node scripts/lint-allow-test-rule-refs.cjs && node scripts/lint-resolution-provenance.cjs",
+    "lint:ci": "npm run lint && npm run lint:skill-deps && npm run lint:generated-sync && node scripts/lint-test-file-count.cjs && node scripts/lint-command-contract.cjs && node scripts/lint-pr-check-project-dir.cjs && npm run lint:legacy-name && node scripts/lint-regression-test-names.cjs && node scripts/lint-allow-test-rule-refs.cjs && node scripts/lint-resolution-provenance.cjs",
     "lint:allow-test-rule-refs": "node scripts/lint-allow-test-rule-refs.cjs",
     "lint:regression-names": "node scripts/lint-regression-test-names.cjs",
     "lint:descriptions": "node scripts/lint-descriptions.cjs",
@@ -105,6 +105,7 @@
     "lint:test-file-count": "node scripts/lint-test-file-count.cjs",
     "lint:pr-checks": "node scripts/lint-pr-check-project-dir.cjs",
     "lint:changeset": "node scripts/changeset/lint.cjs",
+    "lint:generated-sync": "node scripts/gen-capability-registry.cjs --check && node scripts/gen-loop-host-contract.cjs --check && node scripts/gen-capability-matrix.cjs --check && node scripts/sync-manifest-versions.cjs --check && node scripts/gen-inventory-manifest.cjs --check && node scripts/generate-package-identity.cjs --check && node scripts/gen-plugin-skills.cjs --check",
     "lint:docs": "node scripts/lint-docs-required.cjs",
     "lint:legacy-name": "node scripts/lint-legacy-dir-name.cjs",
     "ci:test-scope": "node scripts/ci-test-scope.cjs",