router: T8 note: formats.md 4.4/4.6 corrections

phase-ends/current/PHASE_PLAN.md

@@ -101,3 +101,4 @@ C0507 (§458 struct spelling per-access dial), C0508 (§459 declaration-layer by
 - 2026-09-29 router: T4 next -> done
 - 2026-09-30 critic: reopened T5 as T5.1 — long tail — one definition per type (gate reading fixed)
 - 2026-09-30 router: developer: milestone reading for --check-structs: dup_classes gates tier-1 plus unlisted tier-2 (docs/struct-twins.md with per-class evidence); outside_canon excludes object-declaring block-scope stack frames (reported block_frames=N); dead counts intra-canon uses. Header line unchanged; verified by exit 0 under this reading
+- 2026-09-30 developer: T8 also corrects docs/formats.md §4.4 (the game does NOT expect a zero-filled LZSS ring: the ring lives in scratchpad 0x1F800000 and is never cleared, so a valid stream must not read an unwritten slot) and adds to §4.6 the rule that a type-4 stream's terminator must land in the same 2048-byte sector as in the retail file (the decoder drops the rest of that sector and the loader then checks the next sector for the PAC magic; e.g. SC01.CD sub-file 1 stream must be 407,553-409,600 bytes); evidence: src/800.c LzssDecodeSector ~5465-5515, sector callback ~7198/7315, discussion of issue #2