Add panel detection dependencies

Add ML and computer vision libraries for manga/comic panel detection:
- @techstark/opencv-js: OpenCV.js for edge detection and contour analysis
- @tensorflow/tfjs: TensorFlow.js for ML-based detection fallback
- @tensorflow-models/coco-ssd: Pre-trained COCO-SSD model for object detection

These libraries enable a multi-tier panel detection pipeline:
1. OpenCV edge detection (fast, ~80% accuracy)
2. ML-based detection with COCO-SSD (handles irregular layouts)
3. Grid-based fallback (always works)

All libraries are lazy-loaded on-demand to minimize initial bundle size.

package.json

@@ -16,6 +16,11 @@
   "exports": {
     "./*.js": "./*.js"
   },
+  "dependencies": {
+    "@techstark/opencv-js": "^4.12.0",
+    "@tensorflow/tfjs": "^4.22.0",
+    "@tensorflow-models/coco-ssd": "^2.2.3"
+  },
   "devDependencies": {
     "@eslint/js": "^9.9.1",
     "@rollup/plugin-node-resolve": "^15.2.3",