chore(gates): retire the external pre-commit hook contract

Why: .pre-commit-hooks.yaml and its release-tag gate served external
consumers that do not exist. No repo on the Gitea instance pins these
hooks, and the README names apm as the only supported install path. The
mechanism was also already failing: skill-size-check.sh changed after
v2.0.1 with no tag cut, and the gate cannot fire through Gitea's merge
button. (Simplification audit finding 36.)

Implementation Notes:
- Delete .pre-commit-hooks.yaml, scripts/check-release-needed.sh,
  tests/test-check-release-needed.sh and tests/test-vale-hooks-consumer.sh,
  and remove the check-release-needed pre-push hook. The repo: local
  skill-size-check and vale-audit-prefilter-* hooks are unchanged.
- ADR-0014 is amended, not retired: its runtime decision to bundle Vale
  inside factory-audit stands. The amendment keeps the entry[0]-only
  constraint (LESSONS.md:101,105) in case the export returns. ADR-0025
  gets a pointer.
- test-vale-wrap.sh: drop case 33 (the cross-manifest drift check) and
  case 28's hook-scope half, which read the published manifest. Case 32
  now also requires each hook to select every tracked file of its class,
  which keeps case 33's one-plugin-narrowing guard, with a mutation test.
- test-skill-size-check.sh and test-adr0020-contract.sh now assert the
  hook contract and verbose: true on .pre-commit-config.yaml only.
- gates.md: pre-push count goes from 9 to 8 authored hooks (11 to 10
  reported), and the Release table, the External consumers section and
  the two-manifest scope table are removed. README and script/test
  comments no longer describe the export as live. The resolver comment
  is edited identically in both copies.
- The v1.0.0/v2.0.0/v2.0.1 tags are left in place; they are inert.

ADR: 0014
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

tests/test-skill-size-check.sh

@@ -738,8 +738,8 @@ expect_gate "a fixture with no authoring root reports DID NOT RUN and exits 0" \
 # provider-adapter-author's validate-adapter.sh and the one vale-wrap.sh already
 # used: {0,1} are verdicts, 2 is "you invoked this wrong".
 #
-# SAFE FOR THE HOOK. Both manifests declare pass_filenames: true and neither
-# sets always_run, and pre-commit skips a filename-passing hook outright when
+# SAFE FOR THE HOOK. The skill-size-check hook declares pass_filenames: true
+# and does not set always_run, and pre-commit skips a filename-passing hook outright when
 # its `files:` pattern matches nothing, so pre-commit never invokes this script
 # with an empty argument list. That claim is asserted below rather than left in
 # prose, so a config edit that turns it false fails here.
@@ -773,7 +773,7 @@ if [[ $CLEAN_RC -eq 0 && $FINDING_RC -eq 1 && $USAGE_RC -eq 2 ]]; then
 else
   fail "exit codes collide — clean=$CLEAN_RC findings=$FINDING_RC usage=$USAGE_RC"
 fi
-# The hook contract the usage exit depends on. If either manifest ever stops
+# The hook contract the usage exit depends on. If the hook ever stops
 # passing filenames, or starts always_run, pre-commit could invoke the script
 # with no paths and exit 2 would break the hook rather than diagnose a caller.
 HOOK_CONTRACT="$(python3 - "$REPO_ROOT" <<'PYHOOK'
@@ -805,19 +805,11 @@ for repo in cfg.get('repos') or []:
             found = hook
 check('.pre-commit-config.yaml skill-size-check', found)
 
-with open(os.path.join(root, '.pre-commit-hooks.yaml'), encoding='utf-8') as fh:
-    hooks = yaml.safe_load(fh) or []
-found = None
-for hook in hooks:
-    if isinstance(hook, dict) and hook.get('id') == 'kyberforge-skill-size-check':
-        found = hook
-check('.pre-commit-hooks.yaml kyberforge-skill-size-check', found)
-
 print('; '.join(problems))
 PYHOOK
 )"
 if [[ -z "$HOOK_CONTRACT" ]]; then
-  pass "both manifests pass filenames and neither is always_run, so pre-commit never invokes the script with no paths"
+  pass "the hook passes filenames and is not always_run, so pre-commit never invokes the script with no paths"
 else
   fail "the usage exit would break the hook: $HOOK_CONTRACT"
 fi