IOS LLE: optional Broadway hardware window after a WiiConnect24 shutdown reply (StarletOS phase 11 J1)

Co-Authored-By: Claude Opus 5.5 <[email protected]>

docs/StarletOS_Handoff.md

@@ -233,3 +233,19 @@ creation -106 ("system files corrupted" in the System Menu), in the fork only.
 - The companion's images use, besides these (16 `smlabb`, 4 `smulbb`), only
   `blx`, `clz`, `ldrd`, `strd` among the ARMv5TE additions; those were
   already handled.
+
+## Broadway hardware window after the WiiConnect24 shutdown — 2026-10-06
+
+Companion proposal J1 (approved). With the DSP fix, the companion's System
+Menu under Revolution reaches ES LAUNCH in the fork, while on the console it
+stops right after the WiiConnect24 shutdown reply (IOCTL 0x28), with no IPC
+until then. This lists what Broadway touches in that gap.
+
+- `DOLPHIN_HW_WINDOW=1` (with `DOLPHIN_IPC_TRACE=1`): the IPC trace remembers
+  an IOCTL 0x28 with 32-byte input and output; its reply opens a window, and
+  `MMU::ReadFromHardware`/`WriteToHardware` log each Broadway MMIO access as
+  `HWTRACE R|W address/size value PC` until Broadway's next IPC request (or
+  20000 accesses). `IsOptimizableMMIOAccess` returns 0 while requested, so the
+  JIT inlines no MMIO read. Nothing changes without the variables.
+- `MMU.cpp` and `WII_IPC.h` are now exact integration files (28).
+- 96 Starlet tests passed; both builds rebuilt.