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

apps/api/src/routes/tools/compare.ts

@@ -3,6 +3,7 @@ import { writeFile } from "node:fs/promises";
 import { join } from "node:path";
 import type { FastifyInstance } from "fastify";
 import sharp from "sharp";
+import { ensureSharpCompat } from "../../lib/heic-converter.js";
 import { createWorkspace } from "../../lib/workspace.js";
 
 /**
@@ -41,6 +42,10 @@ export function registerCompare(app: FastifyInstance) {
     }
 
     try {
+      // Decode HEIC/HEIF if needed
+      bufferA = await ensureSharpCompat(bufferA);
+      bufferB = await ensureSharpCompat(bufferB);
+
       // Normalize both to same size for comparison
       const metaA = await sharp(bufferA).metadata();
       const metaB = await sharp(bufferB).metadata();