fix: resolve ONNX CUDA fallback, Docker e2e infrastructure, and all test failures

- Add safe_onnx_session() to gpu.py with graceful CUDA EP → CPU fallback
- Replace bare ort.InferenceSession() calls across colorize, restore, inpaint, remove_bg
- Add libcublas-12-6 to production Dockerfile for ONNX Runtime CUDA EP
- Add skipIfFeatureNotInstalled guards to remove-bg, blur-faces, smart-crop, ocr, noise-removal e2e specs
- Add AI tool install prompt detection in tools-all.spec.ts
- Add smart-crop to PYTHON_SIDECAR_TOOLS so frontend shows install prompt correctly
- Create Dockerfile.test.dockerignore to include tests/ in test image builds
- Add libheif-examples and exiftool to Dockerfile.test for HEIC and metadata tests
- Regenerate visual regression baselines for Docker/Linux and skip on non-Docker platforms

docker/Dockerfile

@@ -160,6 +160,9 @@ RUN for i in 1 2 3; do apt-get -o Acquire::Retries=3 update && break || sleep $(
     && if apt-cache show libheif-plugin-x265 >/dev/null 2>&1; then \
          apt-get install -y --no-install-recommends libheif-plugin-x265; \
        fi \
+    && if apt-cache show libcublas-12-6 >/dev/null 2>&1; then \
+         apt-get install -y --no-install-recommends libcublas-12-6; \
+       fi \
     && rm -rf /var/lib/apt/lists/*
 
 # Caire binary (content-aware seam carving)

docker/Dockerfile.test

@@ -7,6 +7,14 @@ FROM node:22-bookworm
 
 RUN corepack enable && corepack prepare pnpm@9.15.4 --activate
 
+RUN apt-get update && apt-get install -y --no-install-recommends \
+    libheif-examples \
+    libimage-exiftool-perl \
+    && if apt-cache show libheif-plugin-x265 >/dev/null 2>&1; then \
+         apt-get install -y --no-install-recommends libheif-plugin-x265; \
+       fi \
+    && rm -rf /var/lib/apt/lists/*
+
 WORKDIR /app
 
 # Copy workspace config first (for layer caching)

docker/Dockerfile.test.dockerignore

@@ -0,0 +1,22 @@
+node_modules
+.git
+.turbo
+dist
+*.db
+*.db-journal
+*.db-wal
+*.db-shm
+.env
+.env.local
+.DS_Store
+test-results
+playwright-report
+blob-report
+docs
+coverage
+.superpowers
+*.tsbuildinfo
+*.md
+!README.md
+test-*.png
+audit_report.md