fix: resolve all audit findings — e2e coverage, feature system hardening, visual baselines

- Add 8 new E2E specs for AI tools (upscale, enhance-faces, colorize,
  restore-photo, erase-object, smart-crop, passport-photo, red-eye-removal)
  closing all HIGH/MEDIUM coverage gaps from the test matrix audit
- Fix ensureAiDirs() crash on non-Docker environments by gating on
  isDockerEnvironment() — prevents ENOENT when /data doesn't exist
- Bump torch 2.6.0→2.7.0 and torchvision 0.21.0→0.22.0 in feature
  manifest for broader Python version compatibility
- Add Python 3.14 version guard warning in install_feature.py
- Remove duplicate torchvision shims from upscale.py and enhance_faces.py
  (dispatcher.py already handles this at startup)
- Remove orphaned tools.batch i18n key and dead pipeline-builder filter
- Regenerate 4 visual regression baselines for current UI state
- Add data-testid to passport-photo generate button for E2E testability

packages/shared/src/i18n/en.ts

@@ -165,7 +165,6 @@ export const en = {
       description: "Convert images to base64 strings for embedding in HTML, CSS, and more",
     },
     pipeline: { name: "Pipeline Builder", description: "Chain multiple tools into a workflow" },
-    batch: { name: "Batch Processing", description: "Apply any tool to multiple images" },
   },
   settings: {
     title: "Settings",