Rebuild spec: a worker streams its whole range in one request

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

REBUILD.md

@@ -29,7 +29,13 @@ dropping garbage; 28 TB of compressed overview traffic. Throughput goal:
    the time, independent of how fast workers are. A lease goes to a range
    that is already (partly) spooled; a worker reads its chunks from the
    spool, waiting only for chunks still being fetched, and falls back to a
-   direct relay fetch for a range that isn't spooled. Spooled chunks are
+   direct relay fetch for a range that isn't spooled. A worker gets its
+   whole range in one streaming request (`GET /ranges/:id/stream`): the
+   spooled chunks in order, waiting for those still being fetched. It still
+   parses chunk by chunk (2 M lines are ~560 MB of text) and posts results
+   per batch, moving the range's resume point. Chunks matter on the NNTP
+   side: a compressed XOVER reply can't be resumed, old ranges answer
+   slowly, and chunks of one range can be fetched in parallel. Spooled chunks are
    deleted when their range's results are stored, and fetched again if a
    range is leased again later.
    Order: oldest era first (2008–2018 holds 63% of the readable files on