Rebuild: edge:bench, and its result in the spec (TypeScript is fast enough)

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

REBUILD.md

@@ -41,8 +41,11 @@ dropping garbage; 28 TB of compressed overview traffic. Throughput goal:
    Order: oldest era first (2008–2018 holds 63% of the readable files on
    17% of the lines), then forward.
 
-2. **Edge worker** (node, TypeScript reusing `lib/`; Rust later only if
-   CPU-bound). Per lease: compressed chunks of 10–50 k lines, in order →
+2. **Edge worker** (node, TypeScript reusing `lib/`). Measured (`edge:bench`,
+   2026-10-09): 73 k headers/s per core on an a.b.ath range from 2013,
+   103 k/s on a recent a.b.boneless range (2 M headers each), ~1.2 GB peak
+   per process; the 25 B lines/day goal needs ~3–4 cores over all nodes,
+   so no Rust. Per lease: compressed chunks of 10–50 k lines, in order →
    parse subjects → skip crossposts outside their owner group (of the
    indexed groups in the article's Xref, the one with the lowest priority
    number; see the group list) → group articles into files → files