The E3 driver flip makes build_one_sep the sole path; it writes
.sepwork/*.unit.ww, not <stem>.combined.ww, so the flip stops producing
combined.ww. Migrate its consumers to sep-feed first, while both build
paths still exist (reversible; all 5 stage binaries stay byte-identical):
- 990_selfhost: resolveunit drives `ww build --sep` and reads
<stem>.sepwork/__root.unit.ww; probe_cgen_match gains err.ww (sep
inlines fmt's .wwi only, so cs==ww holds); probe_ww_links re-expressed
as `ww_ww build --sep`->run; probe_bootstrap_fixed_point removed (the
monolith path it tested is deleted by E4 -- the self-application axis
lives in `make bootstrap`, the cs==ww axis in 995).
- 994_w6c_ww: drop the combined-fed emit_eq + corpus; keep the live
per-package cs-sep==ww-sep oracle (cmp_sepwork + diff_one + bad[]).
- #110 combined_ww_fresh gate removed (its regen-vs-committed premise
dies with its producer).
Non-vacuity proven: a one-line emitter mutation reddens 994's per-package
cs!=ww check across 15 packages; revert restores green.
Hojun-Cho
5f85852faf