docs: record v3-byte in the 2026-10-22 summary

docs/summary_session-2026-10-22.md

@@ -147,6 +147,7 @@ Three tagged states, each green on all gates:
 | `c02fd41` | `v3-libc-prototypes` | typed libc prototypes, `printf` varargs (+6) |
 | `713650f` | `v3-system-types` | ISO SYSTEM sized types + qualified `SYSTEM` (+8) |
 | `f236600` | `v3-proc-types` | ISO procedure-type syntax (+4) |
+| `7621f16` | `v3-byte` | true 8-bit `BYTE`/`SBYTE` storage |
 
 ## Lessons