* filer: fold small chunks into manifests 256 at a time
Every metadata event carries the file's whole chunk list, so a file grown
by small appends re-sent each chunk record on every append until the
list reached ManifestBatch (10000). Chunks under 1 MiB now fold once 256
of them build up; full-size chunks still fold at ManifestBatch, so large
files keep their flat lists and read without a manifest fetch.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
* filer: merge appended small chunks at the small-chunk fold count
The append path merges small chunks into full-size ones, but only at
1000 of them; the fold now hides small chunks in a manifest at 256, so
the merge would never see enough of them. Merging at the same count
keeps rewriting them into full chunks first.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
---------
Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>