feat(v2): add safe AI fallback and cache/reanalysis decision

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

logic/cache.test.js

@@ -0,0 +1,30 @@
+const { test } = require('node:test');
+const assert = require('node:assert/strict');
+const { needsReanalysis } = require('./cache');
+
+test('sem memoria previa, sempre precisa de IA', () => {
+  const result = needsReanalysis({ memory: null, currentHash: 'abc', now: 1000 });
+  assert.equal(result.needsAi, true);
+  assert.equal(result.reason, 'no_cache');
+});
+
+test('hash igual e sem next_review_at vencido usa cache', () => {
+  const memory = { last_context_hash: 'abc', next_review_at: null };
+  const result = needsReanalysis({ memory, currentHash: 'abc', now: 1000 });
+  assert.equal(result.needsAi, false);
+  assert.equal(result.reason, 'cache_valid');
+});
+
+test('hash diferente forca reavaliacao (mudanca significativa)', () => {
+  const memory = { last_context_hash: 'abc', next_review_at: null };
+  const result = needsReanalysis({ memory, currentHash: 'xyz', now: 1000 });
+  assert.equal(result.needsAi, true);
+  assert.equal(result.reason, 'context_changed');
+});
+
+test('next_review_at vencido forca reavaliacao mesmo com hash igual', () => {
+  const memory = { last_context_hash: 'abc', next_review_at: 500 };
+  const result = needsReanalysis({ memory, currentHash: 'abc', now: 1000 });
+  assert.equal(result.needsAi, true);
+  assert.equal(result.reason, 'review_due');
+});