test(core): fix contradictory composition-discovery file-tree test (#1385) (#1399)

#1385 ("exclude dot-directories from composition discovery", b952dc9c)
merged with a failing test, leaving main red. Its commit message assumed
"walkDir only skipped three exact names (.thumbnails, node_modules, .git)",
but `.hyperframes` had already been added to walkDir's IGNORE_DIRS by the
backup feature (with its own passing "hides internal backup files" test).

So the new test "keeps dot-directory files visible in the file tree" used
`.hyperframes/examples/preset.html` — the one dot-dir that walkDir hides —
and asserted it appears in `files`, which can never hold: `files = walkDir(...)`
filters `.hyperframes`. The implementation is coherent; the test picked the
wrong fixture and never exercised the isInHiddenOrVendorDir gating it meant to.

Fix the fixtures (test-only, no production change):
- Add a genuinely-vendored dot-dir `.cache/examples/preset.html` — walkDir does
  not special-case it, so it stays in the file tree but must be gated out of
  composition discovery by isInHiddenOrVendorDir. This is what #1385 actually
  targets, now properly exercised.
- Keep `.hyperframes/examples/preset.html` and assert it is hidden from the file
  tree (IGNORE_DIRS) — documenting the deliberate divergence so the two features
  (Studio-internal backups vs. browsable vendored dot-dirs) don't collide again.

Full non-producer suite green; the walkDir "hides backups" test is untouched.

Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

packages/core/src/studio-api/routes/projects.test.ts

@@ -17,14 +17,22 @@ afterEach(() => {
 const COMPOSITION_HTML = '<html><body><div data-composition-id="main"></div></body></html>';
 
 // Project layout for #1384: real compositions at the root and under
-// compositions/, plus vendored example HTML inside dot-directories that
+// compositions/, plus two kinds of dot-directory content that exercise
-// must not surface as compositions.
+// discovery gating differently:
+//   - .cache/        a vendored dot-directory. walkDir does NOT special-case it,
+//                    so its HTML stays listed in the file tree, but it must be
+//                    gated out of composition discovery by isInHiddenOrVendorDir.
+//   - .hyperframes/  Studio's own internal directory (backups, etc.) — already in
+//                    walkDir's IGNORE_DIRS, so it is hidden from the file tree
+//                    entirely (and therefore from compositions too).
 function createProjectDir(): string {
   const projectDir = mkdtempSync(join(tmpdir(), "hf-projects-test-"));
   tempDirs.push(projectDir);
   writeFileSync(join(projectDir, "index.html"), COMPOSITION_HTML);
   mkdirSync(join(projectDir, "compositions"));
   writeFileSync(join(projectDir, "compositions", "scene.html"), COMPOSITION_HTML);
+  mkdirSync(join(projectDir, ".cache", "examples"), { recursive: true });
+  writeFileSync(join(projectDir, ".cache", "examples", "preset.html"), COMPOSITION_HTML);
   mkdirSync(join(projectDir, ".hyperframes", "examples"), { recursive: true });
   writeFileSync(join(projectDir, ".hyperframes", "examples", "preset.html"), COMPOSITION_HTML);
   return projectDir;
@@ -59,10 +67,11 @@ describe("registerProjectRoutes — composition discovery (#1384)", () => {
     expect(response.status).toBe(200);
     expect(payload.compositions).toContain("index.html");
     expect(payload.compositions).toContain("compositions/scene.html");
+    expect(payload.compositions).not.toContain(".cache/examples/preset.html");
     expect(payload.compositions).not.toContain(".hyperframes/examples/preset.html");
   });
 
-  it("keeps dot-directory files visible in the file tree", async () => {
+  it("lists vendored dot-directory files in the file tree but hides Studio-internal ones", async () => {
     const projectDir = createProjectDir();
     const app = new Hono();
     registerProjectRoutes(app, createAdapter(projectDir));
@@ -70,6 +79,9 @@ describe("registerProjectRoutes — composition discovery (#1384)", () => {
     const response = await app.request("http://localhost/projects/demo");
     const payload = (await response.json()) as { files?: string[] };
 
-    expect(payload.files).toContain(".hyperframes/examples/preset.html");
+    // Vendored dot-dirs stay browsable — discovery is gated, the file tree is not.
+    expect(payload.files).toContain(".cache/examples/preset.html");
+    // Studio's internal dir is hidden from the tree entirely (walkDir IGNORE_DIRS).
+    expect(payload.files).not.toContain(".hyperframes/examples/preset.html");
   });
 });