feat: SOTA image enhancement with one-click auto-improve (#55)

* feat(image-enhancement): add analysis and correction types

* feat(image-enhancement): implement auto-enhance analysis and correction engine

* test(image-enhancement): add unit tests for auto-enhance engine

* feat(image-enhancement): add API route with analyze endpoint and register in constants/i18n

* feat(image-enhancement): add UI component with mode selector, intensity slider, and analysis badges

* test(image-enhancement): add integration and e2e tests

* fix(image-enhancement): use modulate instead of gamma for exposure correction

Sharp's gamma() only accepts values between 1.0 and 3.0, but brightening
underexposed images computed gamma < 1.0. Switch to modulate({ brightness })
which handles both brightening and darkening correctly.

---------

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

packages/shared/src/constants.ts

@@ -161,6 +161,14 @@ export const TOOLS: Tool[] = [
     icon: "Focus",
     route: "/smart-crop",
   },
+  {
+    id: "image-enhancement",
+    name: "Image Enhancement",
+    description: "One-click auto-improve with smart analysis",
+    category: "ai",
+    icon: "Sparkles",
+    route: "/image-enhancement",
+  },
   // Watermark & Overlay
   {
     id: "watermark-text",

packages/shared/src/i18n/en.ts

@@ -71,6 +71,11 @@ export const en = {
       name: "Smart Crop",
       description: "Smart subject, face, or trim-based cropping",
     },
+    "image-enhancement": {
+      name: "Image Enhancement",
+      description:
+        "One-click auto-improve with smart exposure, contrast, color, and sharpness correction",
+    },
     "content-aware-resize": {
       name: "Content-Aware Resize",
       description: "Intelligently resize images while preserving important content",