feat: comprehensive HEIC/HEIF support and edit-metadata ExifTool overhaul

- Add ensureSharpCompat() helper for automatic HEIC detection and decode
- Fix HEIC support in all 14 custom-route tools (image-to-pdf, split,
  barcode-read, compose, collage, stitch, compare, find-duplicates,
  color-palette, watermark-image, vectorize, favicon, info, branding)
- Fix PdfPagePreview using store's decoded blobUrl instead of raw File
- Add onError fallback in ImageViewer for unrenderable formats
- Fix image-to-pdf progress bar with flushSync for reliable rendering
- Add ExifTool backend for edit-metadata (GPS, keywords, IPTC, dates)
- Rename Strip Metadata to Remove Metadata with interactive Leaflet map
- Fix user-files thumbnail generation for stored HEIC files
- Fix info tool stats() histogram for HEIC via decoded buffer
- Skip HEIC preprocessing in batch route for metadata tools

packages/shared/src/constants.ts

@@ -57,7 +57,7 @@ export const TOOLS: Tool[] = [
   // Optimization
   {
     id: "strip-metadata",
-    name: "Strip Metadata",
+    name: "Remove Metadata",
     description: "Remove EXIF, GPS, and camera info",
     category: "optimization",
     icon: "ShieldOff",