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/user-files.ts

@@ -11,6 +11,7 @@
  */
 import { randomUUID } from "node:crypto";
 import { createReadStream } from "node:fs";
+import { readFile } from "node:fs/promises";
 import { extname } from "node:path";
 import { and, desc, eq, like, sql } from "drizzle-orm";
 import type { FastifyInstance, FastifyReply, FastifyRequest } from "fastify";
@@ -27,6 +28,7 @@ import {
 } from "../lib/file-storage.js";
 import { validateImageBuffer } from "../lib/file-validation.js";
 import { sanitizeFilename } from "../lib/filename.js";
+import { ensureSharpCompat } from "../lib/heic-converter.js";
 import { getAuthUser, requireAuth } from "../plugins/auth.js";
 
 // ── Helpers ────────────────────────────────────────────────────────
@@ -368,7 +370,10 @@ export async function userFileRoutes(app: FastifyInstance): Promise<void> {
       const filePath = getStoredFilePath(file.storedName);
 
       try {
-        const thumbnail = await sharp(filePath)
+        // Read file and decode HEIC/HEIF if needed before Sharp processing
+        const fileBuffer = await ensureSharpCompat(await readFile(filePath));
+
+        const thumbnail = await sharp(fileBuffer)
           .resize(300, null, { withoutEnlargement: true })
           .jpeg({ quality: 80 })
           .toBuffer();