https://gitlab.synchro.net/main/sbbs/-/commit/dd0ebc1455b32147f12300db
Modified Files:
src/doors/syncconquer/door/door.h door_io.c
Log Message:
syncconquer: drop the PPM tier

No terminal could reach it. CTDA capability 4 is a single bit meaning
"pixel operations", covering sixel and PPM together (cterm.adoc), so a
SyncTERM reporting PPM always reports sixel too -- and sixel was tested
first. The only client that could have fallen through to PPM was a
SyncTERM that had NOT advertised pixel operations, which predates cterm's
PPM support by two years and cannot decode DrawPPM at all. cterm gained
sixel in 2018 and PPM in 2022; there has never been a build with one and
not the other.

That left PPM as a manual F4 choice for the two-year window of SyncTERM
builds having PPM but not yet JXL (2024) -- where it is strictly worse
than the sixel those same clients already have: 640x400 ships about a
megabyte a frame against sixel's ~150KB, and a raw P6 carries no
colorspace tag, so SyncTERM decodes our sRGB pixels as BT.709 and the
colors come out wrong.

Removes the tier, its encoder, and its buffers. Sixel and JXL are now the
only pixel tiers, which is what the dirty-rect paths already assumed.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

---
þ Synchronet þ Vertrauen þ Home of Synchronet þ [vert/cvs/bbs].synchro.net