New-app checklist: reviewed, a gate (onboarding), the wger pilot record, the existing apps' gap page

NEW-APP-CHECKLIST.md: the reviewer's draft reviewed - 60 rows in 10 groups, each with how/why and a since date;
7 rows added, 16 sharpened, 9 wrong claims fixed. onboarding/_TEMPLATE.md (one line per id), onboarding/wger.md
(the pilot, exempt app, 11 open rows each a register row), onboarding/EXISTING-APPS-GAPS.md (read only, from
scripts/onboarding_gaps.py). Gate onboarding (scripts/check-onboarding.py) in --fast: a template directory not
among the 53 published before 2026-10-01 needs a complete record; decoys in test_gate_decoys.py (16 cases, 5 gate
mutants seen red). CLAUDE.md, REUSE.md 5, README point to it. No template changed.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0159rPz1ZhFKsS53msqPYxtS

scripts/test_catalog_gates.py

@@ -62,7 +62,9 @@ class CatalogGatesFastTest(unittest.TestCase):
         # (copy-i18n, probe-matches-compose) — the test was red and nobody ran it. Now 9 with the test
         # record's two halves; the slow pair stays out of --fast. STALE AGAIN until 2026-09-30: 10 since
         # probe-measured joined; the test had been red on main (found by the more-night-apps session).
-        self.assertEqual(len(mod.GATES), 10)
+        # 11 since 2026-10-01: onboarding (NEW-APP-CHECKLIST.md), fast and history-free, so it runs in CI too.
+        self.assertEqual(len(mod.GATES), 11)
+        self.assertIn("onboarding", [g[0] for g in mod.GATES if g[3] and not g[4]])
         self.assertEqual([g[0] for g in mod.GATES if not g[3]], ["image-resolvable", "volume-persistence"])
         self.assertIn("test-record", [g[0] for g in mod.GATES if g[3] and not g[4]])  # runs in CI too
         # the gates that need git history are the ones the CI half cannot run (R-452's shallow gap)