test: add Round 104 edge-case tests (detectFromLockFile null, resolveSessionAlias traversal, whitespace notes)

- detectFromLockFile(null): throws TypeError — no input validation before
  path.join (package-manager.js:95)
- resolveSessionAlias('../etc/passwd'): returns path-traversal input unchanged
  when alias lookup fails, documenting the passthrough behavior
- parseSessionMetadata with whitespace-only notes: trim() → "" → hasNotes=false,
  whitespace-only notes treated as absent

Total tests: 872 (all passing)

tests/lib/package-manager.test.js

@@ -1455,6 +1455,20 @@ function runTests() {
     }
   })) passed++; else failed++;
 
+  // ── Round 104: detectFromLockFile with null projectDir (no input validation) ──
+  console.log('\nRound 104: detectFromLockFile (null projectDir — throws TypeError):');
+  if (test('detectFromLockFile(null) throws TypeError (path.join rejects null)', () => {
+    // package-manager.js line 95: `path.join(projectDir, pm.lockFile)` — there is no
+    // guard checking that projectDir is a string before passing it to path.join().
+    // When projectDir is null, path.join(null, 'package-lock.json') throws a TypeError
+    // because path.join only accepts string arguments.
+    assert.throws(
+      () => pm.detectFromLockFile(null),
+      { name: 'TypeError' },
+      'path.join(null, ...) should throw TypeError (no input validation in detectFromLockFile)'
+    );
+  })) passed++; else failed++;
+
   // Summary
   console.log('\n=== Test Results ===');
   console.log(`Passed: ${passed}`);

tests/lib/session-aliases.test.js

@@ -1355,6 +1355,26 @@ function runTests() {
       'Object.keys of array returns numeric string indices, not named alias keys');
   })) passed++; else failed++;
 
+  // ── Round 104: resolveSessionAlias with path-traversal input (passthrough without validation) ──
+  console.log('\nRound 104: resolveSessionAlias (path-traversal input — returned unchanged):');
+  if (test('resolveSessionAlias returns path-traversal input as-is when alias lookup fails', () => {
+    // session-aliases.js lines 365-374: resolveSessionAlias first tries resolveAlias(),
+    // which rejects '../etc/passwd' because the regex /^[a-zA-Z0-9_-]+$/ fails on dots
+    // and slashes (returns null). Then the function falls through to line 373:
+    // `return aliasOrId` — returning the potentially dangerous input unchanged.
+    // Callers that blindly use this return value could be at risk.
+    resetAliases();
+    const traversal = '../etc/passwd';
+    const result = aliases.resolveSessionAlias(traversal);
+    assert.strictEqual(result, traversal,
+      'Path-traversal input should be returned as-is (resolveAlias rejects it, fallback returns input)');
+    // Also test with another invalid alias pattern
+    const dotSlash = './../../secrets';
+    const result2 = aliases.resolveSessionAlias(dotSlash);
+    assert.strictEqual(result2, dotSlash,
+      'Another path-traversal pattern also returned unchanged');
+  })) passed++; else failed++;
+
   // Summary
   console.log(`\nResults: Passed: ${passed}, Failed: ${failed}`);
   process.exit(failed > 0 ? 1 : 0);

tests/lib/session-manager.test.js

@@ -1689,6 +1689,34 @@ src/main.ts
       'Second unchecked item');
   })) passed++; else failed++;
 
+  // ── Round 104: parseSessionMetadata with whitespace-only notes section ──
+  console.log('\nRound 104: parseSessionMetadata (whitespace-only notes — trim reduces to empty):');
+  if (test('parseSessionMetadata treats whitespace-only notes as absent (trim → empty string → falsy)', () => {
+    // session-manager.js line 139: `metadata.notes = notesSection[1].trim()` — when the
+    // Notes section heading exists but only contains whitespace/newlines, trim() returns "".
+    // Then getSessionStats line 178: `hasNotes: !!metadata.notes` — `!!""` is `false`.
+    // So a notes section with only whitespace is treated as "no notes."
+    const content = `# Session
+
+### Notes for Next Session
+   \t
+
+### Context to Load
+\`\`\`
+file.ts
+\`\`\`
+`;
+    const meta = sessionManager.parseSessionMetadata(content);
+    assert.strictEqual(meta.notes, '',
+      'Whitespace-only notes should trim to empty string');
+    // Verify getSessionStats reports hasNotes as false
+    const stats = sessionManager.getSessionStats(content);
+    assert.strictEqual(stats.hasNotes, false,
+      'hasNotes should be false because !!"" is false (whitespace-only notes treated as absent)');
+    assert.strictEqual(stats.hasContext, true,
+      'hasContext should be true (context section has actual content)');
+  })) passed++; else failed++;
+
   // Summary
   console.log(`\nResults: Passed: ${passed}, Failed: ${failed}`);
   process.exit(failed > 0 ? 1 : 0);