fix(upload): surface an 'Analyzing' status during pre-upload file hashing

Computing the torrent info-hash (and the content-hash fallback) reads the entire
file before the upload starts and before any progress is emitted, so on
multi-GB videos there was a long silent pause that looked like a freeze. Both
upload services now emit an 'Analyzing video…' status when a full-file hash is
required (i.e. no valid info-hash was pre-supplied). Cloudflare-upload audit #2.

Test: tests/services/s3-upload-analyzing-status.test.mjs.

Co-Authored-By: Claude Opus 4.8 <[email protected]>

js/services/r2Service.js

@@ -870,6 +870,18 @@ class R2Service {
     this.updateCloudflareProgress(0);
     this.setCloudflareUploading(true);
 
+    // Computing the torrent info-hash (and the content-hash fallback) reads the
+    // ENTIRE file before the upload starts and before any progress is emitted —
+    // on multi-GB videos that's a long, silent pause that looks like a freeze.
+    // Surface a status so the user knows work is happening.
+    const willHashFile = Boolean(file) && !isValidInfoHash(normalizeInfoHash(infoHash));
+    if (willHashFile) {
+      this.setCloudflareUploadStatus(
+        "Analyzing video (large files can take a moment)…",
+        "info",
+      );
+    }
+
     const keyIdentifier = await resolveUploadIdentifier({ infoHash, file });
     const normalizedInfoHash = normalizeInfoHash(infoHash || keyIdentifier);
     const hasValidInfoHash = isValidInfoHash(normalizedInfoHash);