feat: AI face enhancement with GFPGAN and CodeFormer (#61)

* feat(shared): add enhance-faces tool definition and i18n strings

* feat(ai): add face enhancement script with GFPGAN and CodeFormer support

Detects faces via MediaPipe dual-model approach, then enhances using
GFPGAN (proven) or CodeFormer (via codeformer-pip) with auto fallback.
Supports strength-based alpha blending with original image.

* feat(ai): add TypeScript bridge for face enhancement

* feat(api): add enhance-faces route with GFPGAN/CodeFormer support

* feat(web): add enhance-faces settings component and register in tool registry

* feat(docker): add CodeFormer dependency and model download

- Add codeformer-pip to both CPU and GPU requirements
- Download CodeFormer model (~375MB) at Docker build time
- Add CodeFormer to smoke test verification

* fix(enhance-faces): address code review findings

- Skip alpha blend for CodeFormer (strength already applied via fidelity weight)
- Hide "only enhance main face" checkbox when Best (CodeFormer) is selected
- Fix sensitivity slider labels (swap More/Fewer faces to match actual behavior)
- Register EnhanceFacesControls in pipeline step settings
- Remove model names from user-facing descriptions

* fix(enhance-faces): fix CodeFormer integration and Docker setup

- Add codeformer-pip install to Dockerfile with --no-deps to avoid numpy 2.x conflict
- Re-pin numpy==1.26.4 after codeformer-pip install
- Pin codeformer-pip==0.0.4 in requirements files
- Broaden auto-mode fallback to catch any Exception from CodeFormer

---------

Co-authored-by: stirling-image <stirling-image@users.noreply.github.com>

apps/web/src/lib/tool-registry.tsx

@@ -229,6 +229,11 @@ const BlurFacesSettings = lazy(() =>
     default: m.BlurFacesSettings,
   })),
 );
+const EnhanceFacesSettings = lazy(() =>
+  import("@/components/tools/enhance-faces-settings").then((m) => ({
+    default: m.EnhanceFacesSettings,
+  })),
+);
 const EraseObjectSettings = lazy(() =>
   import("@/components/tools/erase-object-settings").then((m) => ({
     default: m.EraseObjectSettings,
@@ -371,6 +376,7 @@ export const toolRegistry = new Map<string, ToolRegistryEntry>([
   ["upscale", { displayMode: "before-after", Settings: UpscaleSettings }],
   ["ocr", { displayMode: "before-after", Settings: OcrSettings }],
   ["blur-faces", { displayMode: "before-after", Settings: BlurFacesSettings }],
+  ["enhance-faces", { displayMode: "before-after", Settings: EnhanceFacesSettings }],
   [
     "erase-object",
     {