Large files buffered entirely in RAM can OOM workers. Add
max_file_size to source config (default None = no limit).
FS checks stat().st_size before read_bytes(). HTTP and WebDAV issue
a HEAD request before GET when a limit is configured. S3 checks the
size from the existing head_async() call before get_async().
FileTooLargeError is classified as PermanentError so oversized files
go straight to the DLQ instead of retrying.
HTTP, S3, and WebDAV sources all check `revision is not None and
snapshot.get(uri) == revision` to decide UPSERT vs UNCHANGED. When
a server returns no ETag or Last-Modified, revision is None and the
condition always fails — every sweep emits UPSERT even though the
content hasn't changed.
Now emit UNCHANGED when revision is None and the URI is already
known (has been ingested before). A first-time discovery with no
revision still correctly emits UPSERT.