fix(worker): route SVG (and other image assets) through the image-poster

path instead of failing the video transcode

Previously IMAGE_CODECS contained the raster ffprobe codec names ('png',
'mjpeg', 'jpeg', 'webp', 'gif', 'tiff', 'bmp', 'jpegls') but not 'svg'.
An SVG-as-asset (e.g. an architecture diagram dragged into a project) was
correctly tagged media_type='image' in the DB but ffprobe reported its
codec as 'svg', which fell through to the video branch, found
durationMs===null, and died with 'Empty or truncated source: codec=svg,
resolution=0x0'. That clogs the failed-jobs list with red rows that have
nothing to do with broken captures.

Two fixes here:

1) Add 'svg' to IMAGE_CODECS so the existing transcodeImage()/poster
   path handles it.

2) Also bail to the poster path when the asset row itself says
   media_type='image', even if ffprobe didn't return a codec name we
   recognize (defensive — catches future formats like AVIF without
   requiring an explicit catalog update).

Closes part of #13.

services/worker/src/workers/proxy.js

@@ -39,7 +39,9 @@ async function loadProxyEncodingSettings() {
 
 // Codec names ffprobe reports for still-image inputs. These bypass the video
 // transcode entirely — see proxyWorker below.
-const IMAGE_CODECS = new Set(['png', 'mjpeg', 'jpeg', 'webp', 'gif', 'tiff', 'bmp', 'jpegls']);
+const IMAGE_CODECS = new Set([
+  'png', 'mjpeg', 'jpeg', 'webp', 'gif', 'tiff', 'bmp', 'jpegls', 'svg',
+]);
 
 const S3_BUCKET = process.env.S3_BUCKET || 'wild-dragon';
 
@@ -66,13 +68,26 @@ export const proxyWorker = async (job) => {
     console.log(`[proxy] Downloading ${inputKey} for asset ${assetId}`);
     await downloadFromS3(S3_BUCKET, inputKey, inputPath);
 
+    // Look up the asset row early — we want media_type before deciding how
+    // to process. That lets us route 'image' assets to the poster path even
+    // when ffprobe doesn't return a codec name in IMAGE_CODECS (e.g. future
+    // formats like AVIF / HEIF / JPEG-XL).
+    const assetRow = await query(
+      'SELECT media_type FROM assets WHERE id = $1',
+      [assetId]
+    );
+    const dbMediaType = assetRow.rows[0]?.media_type || null;
+
     // Reject obviously-empty inputs before handing them to ffmpeg. Aborted
     // SRT/RTMP recordings end up as 0-byte (or ftyp-only ~1KB) objects in S3
     // when the source disconnects before any frame is received; the proxy
     // pipeline used to bomb on "moov atom not found", which buried the
     // real reason. Bail with a clear message and let the asset go to 'error'.
+    //
+    // Skip this check for image assets — a single PNG icon can legitimately
+    // be a few hundred bytes.
     const { size: inputBytes } = await stat(inputPath);
-    if (inputBytes < 4096) {
+    if (dbMediaType !== 'image' && inputBytes < 4096) {
       throw new Error(
         `Source is empty or truncated (${inputBytes} bytes). The recording ` +
         `likely ended before any frames were received — check the source ` +
@@ -95,12 +110,17 @@ export const proxyWorker = async (job) => {
     // Still images skip the video proxy — they have no temporal stream and
     // x264 with a one-frame PNG input fails (Could not open encoder before EOF).
     // Generate a scaled JPEG poster instead; the thumbnail job will downsize it.
-    const isImage = mediaInfo.codec && IMAGE_CODECS.has(mediaInfo.codec.toLowerCase());
+    //
+    // We treat the input as an image if EITHER the DB says so (media_type =
+    // 'image', set by upload.js based on Content-Type or extension), OR
+    // ffprobe reports a codec we know is a still-image format.
+    const codecLower = mediaInfo.codec ? mediaInfo.codec.toLowerCase() : null;
+    const isImage = dbMediaType === 'image' || (codecLower && IMAGE_CODECS.has(codecLower));
 
     if (isImage) {
       const imageOutputKey = outputKey.replace(/\.mp4$/, '.jpg');
       const imageOutputPath = outputPath.replace(/\.mp4$/, '.jpg');
-      console.log(`[proxy] Image asset ${assetId} (${mediaInfo.codec}) — emitting poster instead of video proxy`);
+      console.log(`[proxy] Image asset ${assetId} (codec=${codecLower || 'unknown'}, db_media_type=${dbMediaType}) — emitting poster instead of video proxy`);
       await job.updateProgress(40);
       await transcodeImage(inputPath, imageOutputPath);
       await job.updateProgress(70);