HEIC thumbnails: pull full file (partial reads unreliable for sips conversion)

1MB partial HEIC reads are not sufficient for sips to convert to JPEG.
Revert to full file pull for HEIC thumbnails. Files are cached permanently
so each HEIC is only transferred once — subsequent launches skip already-cached files.

src/main/kotlin/com/bolenpad/photophetch/ui/AppState.kt

@@ -235,26 +235,16 @@ class AppState(private val configStore: ConfigStore) {
                     val cachePath = cacheDir.resolve("$hash.jpg")
                     if (tmpFile.toFile().exists() && tmpFile.toFile().length() > 0 && !cachePath.toFile().exists()) {
                         val success = if (ext in setOf("heic", "heif")) {
-                            // Extract embedded EXIF thumbnail from HEIC (fast, no full decode needed)
-                            // sips -getProperty thumbnail reads only the thumbnail track
+                            // Convert partial HEIC to JPEG via sips
+                            // sips can decode HEIC even from a partial file if the header is intact
                             val sips = ProcessBuilder(
-                                "sips", "-getProperty", "thumbnail",
-                                tmpFile.toString(), "--out", cachePath.toString()
-                            ).redirectErrorStream(true).start()
-                            val output = sips.inputStream.bufferedReader().readText()
-                            sips.waitFor()
-                            val ok = cachePath.toFile().exists() && cachePath.toFile().length() > 0
-                            if (!ok) {
-                                // Thumbnail extraction failed — fall back to full resample
-                                val sips2 = ProcessBuilder(
                                 "sips", "--resampleWidth", "240",
                                 "--setProperty", "format", "jpeg",
                                 tmpFile.toString(), "--out", cachePath.toString()
                             ).redirectErrorStream(true).start()
-                                sips2.inputStream.readBytes()
-                                sips2.waitFor()
+                            sips.inputStream.readBytes()
+                            sips.waitFor()
                             cachePath.toFile().exists() && cachePath.toFile().length() > 0
-                            } else ok
                         } else {
                             // JPEG/PNG: simple resample
                             val sips = ProcessBuilder(

src/main/resources/scripts/photophetch-ios-helper.py

@@ -176,11 +176,16 @@ async def cmd_batch_thumbs(pairs_json: str):
         for device_path, local_path in pairs:
             ext = device_path.rsplit('.', 1)[-1].lower() if '.' in device_path else ''
             is_heic = ext in ('heic', 'heif')
-            read_size = 1024 * 1024 if is_heic else 512 * 1024  # 1MB for HEIC, 512KB for others
             try:
                 os.makedirs(os.path.dirname(os.path.abspath(local_path)), exist_ok=True)
+                if is_heic:
+                    # HEIC: pull full file — sips needs the full image to convert to JPEG
+                    # Cached permanently so only transferred once
+                    await afc.pull(device_path, local_path)
+                else:
+                    # JPEG/PNG: 512KB partial read is sufficient for sips resample
                     try:
-                    data = await afc.fread(device_path, read_size, 0)
+                        data = await afc.fread(device_path, 512 * 1024, 0)
                         with open(local_path, 'wb') as f:
                             f.write(data)
                     except Exception: