fix(enforce): hole 1 — remove self-override via assistant text

Brain-retro #5 candidate C, hole 1: enforce-classifier-match.mjs allowed
the agent to bypass the rule by writing 'override: <reason>' in its own
response (self-override = no enforcement). The user-vocabulary override
phrases in enforce-override-vocab.json remain the only legitimate path.

Added regression test asserting block on assistantText override when user
prompt has no override phrase.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

tools/enforce-classifier-match.mjs

@@ -1,4 +1,4 @@
-#!/usr/bin/env node
+#!/usr/bin/env node
 /**
  * Rule #8 — Classifier-mismatch enforce.
  *
@@ -63,8 +63,8 @@ export function decide({ toolUses, recommendation, confidence, assistantText, ov
   const matched = toolUses.some((u) => nodeMatches(recommendation, u));
   if (matched) return { block: false };
 
-  // Allow explicit override: lines like "override: <reason>" in assistant text.
-  if (assistantText && /\boverride:\s+\S/i.test(assistantText)) return { block: false };
+  // NOTE: prior \ self-bypass removed (retro #5 hole 1) - assistant
+  // cannot grant itself an override. User must use a vocabulary phrase.
 
   return {
     block: true,

tools/enforce-classifier-match.test.mjs

@@ -72,14 +72,26 @@ describe('enforce-classifier-match / decide', () => {
     expect(r.block).toBe(false);
   });
 
-  it('allows when explicit "override:" in assistant text', () => {
+  it('blocks (not allows) when only "override:" in assistant text — self-override removed (hole 1)', () => {
     const r = decide({
       toolUses: [{ name: 'Edit', input: {} }],
       recommendation: 'foo:bar',
       confidence: 0.9,
       assistantText: 'override: simpler direct edit, foo:bar overkill here\n',
+      override: null,
     });
-    expect(r.block).toBe(false);
+    expect(r.block).toBe(true);
+  });
+
+  it('blocks when assistant text has "override: reason" but user prompt has no override phrase (hole 1)', () => {
+    const r = decide({
+      toolUses: [{ name: 'Edit', input: {} }],
+      recommendation: 'superpowers:writing-plans',
+      confidence: 0.9,
+      assistantText: 'override: just doing it quick',
+      override: null,
+    });
+    expect(r.block).toBe(true);
   });
 
   it('allows when override phrase present', () => {