feat: add output filename suffixes, CPU fallback for GPU packages, and fix e2e tests

- Add tool-specific suffix to output filenames so downloads don't overwrite originals (batch & single-tool routes)
- Skip deleting shared models when uninstalling a bundle that shares models with another installed bundle
- Auto-detect NVIDIA GPU and swap GPU-only pip packages (onnxruntime-gpu, paddlepaddle-gpu) for CPU equivalents
- Refactor docker-compose with YAML anchors and explicit cpu/gpu profiles
- Add libheif-plugin-x265 to Dockerfile
- Fix install-all queue logic to handle concurrent individual installs and clear stale errors
- Unify playwright docker config to use same test dir with API_URL env var
- Fix flaky e2e selectors, rename Strip Metadata → Remove Metadata, handle collage custom dropzone, improve fallback test image generation

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

tests/e2e/blur-faces.spec.ts

@@ -31,7 +31,7 @@ test.describe("Blur Faces tool", () => {
 
     // Should complete without the old "cannot identify image file" error
     await expect(
-      page.getByTestId("blur-faces-download").or(page.getByText("No faces detected")),
+      page.getByTestId("blur-faces-download").or(page.getByText("No faces detected")).first(),
     ).toBeVisible({ timeout: 120_000 });
 
     await expect(page.locator("text=cannot identify image")).not.toBeVisible();