fix(context): Improve context building, caching and test robustness

test/test.contextcache.node.ts

@@ -41,7 +41,7 @@ tap.test('ContextCache.init should create cache directory', async () => {
 
   // Check that cache directory was created
   const exists = await fs.promises.access(testCacheDir).then(() => true).catch(() => false);
-  expect(exists).toBe(true);
+  expect(exists).toEqual(true);
 
   await cleanupTestCache();
 });
@@ -56,11 +56,15 @@ tap.test('ContextCache.set should store cache entry', async () => {
   await cache.init();
 
   const testPath = path.join(testProjectRoot, 'package.json');
+  // Get actual file mtime for validation to work
+  const stats = await fs.promises.stat(testPath);
+  const fileMtime = Math.floor(stats.mtimeMs);
+
   const entry: ICacheEntry = {
     path: testPath,
     contents: 'test content',
     tokenCount: 100,
-    mtime: Date.now(),
+    mtime: fileMtime,
     cachedAt: Date.now()
   };
 
@@ -171,10 +175,10 @@ tap.test('ContextCache.has should check if file is cached and valid', async () =
   await cache.set(entry);
 
   const hasIt = await cache.has(testPath);
-  expect(hasIt).toBe(true);
+  expect(hasIt).toEqual(true);
 
   const doesNotHaveIt = await cache.has('/non/existent/path.ts');
-  expect(doesNotHaveIt).toBe(false);
+  expect(doesNotHaveIt).toEqual(false);
 
   await cleanupTestCache();
 });
@@ -384,11 +388,16 @@ tap.test('ContextCache should persist to disk and reload', async () => {
   });
   await cache1.init();
 
+  // Use a real file that exists so validation passes
+  const testPath = path.join(testProjectRoot, 'package.json');
+  const stats = await fs.promises.stat(testPath);
+  const fileMtime = Math.floor(stats.mtimeMs);
+
   const entry: ICacheEntry = {
-    path: '/test/persistent-file.ts',
+    path: testPath,
     contents: 'persistent content',
     tokenCount: 150,
-    mtime: Date.now(),
+    mtime: fileMtime,
     cachedAt: Date.now()
   };
 
@@ -404,8 +413,8 @@ tap.test('ContextCache should persist to disk and reload', async () => {
   });
   await cache2.init();
 
-  const stats = cache2.getStats();
-  expect(stats.entries).toBeGreaterThan(0);
+  const cacheStats = cache2.getStats();
+  expect(cacheStats.entries).toBeGreaterThan(0);
 
   await cleanupTestCache();
 });