feat: inject active instincts into session start context

tests/integration/hooks.test.js

@@ -7,6 +7,7 @@
  */
 
 const assert = require('assert');
+const crypto = require('crypto');
 const path = require('path');
 const fs = require('fs');
 const os = require('os');
@@ -179,6 +180,26 @@ function cleanupTestDir(testDir) {
   fs.rmSync(testDir, { recursive: true, force: true });
 }
 
+function writeInstinctFile(filePath, entries) {
+  const body = entries.map(entry => `---
+id: ${entry.id}
+trigger: "${entry.trigger}"
+confidence: ${entry.confidence}
+domain: ${entry.domain || 'general'}
+scope: ${entry.scope}
+---
+
+## Action
+${entry.action}
+
+## Evidence
+${entry.evidence || 'Learned from repeated observations.'}
+`).join('\n');
+
+  fs.mkdirSync(path.dirname(filePath), { recursive: true });
+  fs.writeFileSync(filePath, body);
+}
+
 function getHookCommandByDescription(hooks, lifecycle, descriptionText) {
   const hookGroup = hooks.hooks[lifecycle]?.find(
     entry => entry.description && entry.description.includes(descriptionText)
@@ -333,6 +354,66 @@ async function runTests() {
     }
   })) passed++; else failed++;
 
+  if (await asyncTest('session-start injects high-confidence instincts into additionalContext', async () => {
+    const testDir = createTestDir();
+    const projectDir = path.join(testDir, 'project');
+    fs.mkdirSync(projectDir, { recursive: true });
+
+    try {
+      const projectId = crypto.createHash('sha256').update(projectDir).digest('hex').slice(0, 12);
+      const homunculusDir = path.join(testDir, '.claude', 'homunculus');
+      const projectInstinctDir = path.join(homunculusDir, 'projects', projectId, 'instincts', 'personal');
+      const globalInstinctDir = path.join(homunculusDir, 'instincts', 'inherited');
+
+      writeInstinctFile(path.join(projectInstinctDir, 'project-instincts.yaml'), [
+        {
+          id: 'project-tests-first',
+          trigger: 'when changing tests',
+          confidence: 0.9,
+          scope: 'project',
+          action: 'Run the targeted *.test.js file first, then widen to node tests/run-all.js.',
+        },
+        {
+          id: 'project-low-confidence',
+          trigger: 'when guessing',
+          confidence: 0.4,
+          scope: 'project',
+          action: 'This should never be injected.',
+        },
+      ]);
+
+      writeInstinctFile(path.join(globalInstinctDir, 'global-instincts.yaml'), [
+        {
+          id: 'global-validation',
+          trigger: 'when editing hooks',
+          confidence: 0.82,
+          scope: 'global',
+          action: 'Keep hook scripts, tests, and docs aligned in the same change set.',
+        },
+      ]);
+
+      const result = await runHookWithInput(
+        path.join(scriptsDir, 'session-start.js'),
+        {},
+        {
+          HOME: testDir,
+          CLAUDE_PROJECT_DIR: projectDir,
+        }
+      );
+
+      assert.strictEqual(result.code, 0, 'SessionStart should exit 0');
+      const payload = getSessionStartPayload(result.stdout);
+      const additionalContext = payload.hookSpecificOutput.additionalContext;
+
+      assert.ok(additionalContext.includes('Active instincts:'), 'Should inject instinct summary into additionalContext');
+      assert.ok(additionalContext.includes('[project 90%] Run the targeted *.test.js file first, then widen to node tests/run-all.js.'), 'Should include project-scoped instinct');
+      assert.ok(additionalContext.includes('[global 82%] Keep hook scripts, tests, and docs aligned in the same change set.'), 'Should include global instinct');
+      assert.ok(!additionalContext.includes('This should never be injected.'), 'Should exclude low-confidence instincts');
+    } finally {
+      cleanupTestDir(testDir);
+    }
+  })) passed++; else failed++;
+
   if (await asyncTest('session-end-marker removes the last lease and stops the observer process', async () => {
     const testDir = createTestDir();
     const projectDir = path.join(testDir, 'project');