test: add 3 tests for suggest-compact, session-aliases, typecheck (Round 64)

- suggest-compact: 'default' session ID fallback when CLAUDE_SESSION_ID empty
- session-aliases: loadAliases backfills missing version and metadata fields
- post-edit-typecheck: valid JSON without tool_input passes through unchanged

Total: 797 tests, all passing

tests/hooks/hooks.test.js

@@ -2999,6 +2999,19 @@ async function runTests() {
       'Should pass through data unchanged when tool_input is absent');
   })) passed++; else failed++;
 
+  // ── Round 64: post-edit-typecheck.js valid JSON without tool_input ──
+  console.log('\nRound 64: post-edit-typecheck.js (valid JSON without tool_input):');
+
+  if (await asyncTest('skips typecheck when JSON has no tool_input field', async () => {
+    const stdinJson = JSON.stringify({ result: 'ok', metadata: { action: 'test' } });
+    const result = await runScript(path.join(scriptsDir, 'post-edit-typecheck.js'), stdinJson);
+
+    assert.strictEqual(result.code, 0, 'Should exit 0 for JSON without tool_input');
+    // input.tool_input?.file_path is undefined → skips TS check → passes through
+    assert.strictEqual(result.stdout, stdinJson,
+      'Should pass through data unchanged when tool_input is absent');
+  })) passed++; else failed++;
+
   // Summary
   console.log('\n=== Test Results ===');
   console.log(`Passed: ${passed}`);

tests/hooks/suggest-compact.test.js

@@ -318,6 +318,30 @@ function runTests() {
     cleanupCounter();
   })) passed++; else failed++;
 
+  // ── Round 64: default session ID fallback ──
+  console.log('\nDefault session ID fallback (Round 64):');
+
+  if (test('uses "default" session ID when CLAUDE_SESSION_ID is empty', () => {
+    const defaultCounterFile = getCounterFilePath('default');
+    try { fs.unlinkSync(defaultCounterFile); } catch {}
+    try {
+      // Pass empty CLAUDE_SESSION_ID — falsy, so script uses 'default'
+      const env = { ...process.env, CLAUDE_SESSION_ID: '' };
+      const result = spawnSync('node', [compactScript], {
+        encoding: 'utf8',
+        input: '{}',
+        timeout: 10000,
+        env,
+      });
+      assert.strictEqual(result.status || 0, 0, 'Should exit 0');
+      assert.ok(fs.existsSync(defaultCounterFile), 'Counter file should use "default" session ID');
+      const count = parseInt(fs.readFileSync(defaultCounterFile, 'utf8').trim(), 10);
+      assert.strictEqual(count, 1, 'Counter should be 1 for first run with default session');
+    } finally {
+      try { fs.unlinkSync(defaultCounterFile); } catch {}
+    }
+  })) passed++; else failed++;
+
   // Summary
   console.log(`\nResults: Passed: ${passed}, Failed: ${failed}`);
   process.exit(failed > 0 ? 1 : 0);