docs: correct the ruler #2 icache_miss value on the 15-loop ROM

The 2026-06-27 MMIO entry in FAITHFUL_TIMING_PLAN.md says the 13 prior
loops were unchanged when mmio_timer and mmio_spu were added. icache_miss
was not: the two new loops sit before it and move its loop top from
0x80010144 to 0x80010170, so each of its two misses costs one cycle more
and it reads +16 on both backends (re-measured against live psx-beetle; the
cycle_testrom README already explains the shift). The entry now carries a
dated correction, and the beetle-macos.md intro no longer points readers
at +14 as the current value.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

docs/beetle-macos.md

@@ -12,7 +12,9 @@ starting from a fresh clone of the official Beetle repository:
 - `ping` answers `backend=beetle`, and `guest_cycles` advances about 565,050
   cycles per frame (33.8688 MHz at 59.94 Hz is 565,045);
 - ruler #2 (`tools/cycle_testrom`) reproduces the oracle values recorded in
-  `internal/FAITHFUL_TIMING_PLAN.md`, `icache_miss +14` included (see step 6).
+  `internal/FAITHFUL_TIMING_PLAN.md` on all 13 loops of the 13-loop ROM
+  (`icache_miss +14`) and on all 15 loops of the current ROM, where
+  `icache_miss` reads +16 (see step 6).
 
 The Linux recipe is in `beetle-linux.md`. The Beetle side of both is the same
 patch set.

docs/internal/FAITHFUL_TIMING_PLAN.md

@@ -896,6 +896,10 @@ on a fixed region -> next.
   rebuild runtime/cyctest. New ruler #2 loops `mmio_timer` (Timer0 read → +3 = 1 dev + 2 compl)
   and `mmio_spu` (32-bit SPU read → +38 = 36 + 2). VALIDATED: cyctest COMPILED (4600) == Beetle
   (4382) EXACT on ALL 15 loops incl. mmio_timer +3 / mmio_spu +38; the 13 prior loops unchanged.
+  (Correction, 2026-09-29: except `icache_miss`, which reads +16 on this 15-loop ROM on both
+  backends, not +14. The two new loops sit before it and move its loop top from 0x80010144 to
+  0x80010170, a different offset in its cache line, so each of its two misses costs one cycle
+  more. Re-measured against live psx-beetle; see tools/cycle_testrom/README.md.)
   Tomba 2 boots past the BIOS to its "SCEA Presents" intro splash, total_checks advancing, no
   freeze (the faster-MMIO change did not trigger a device-timing cascade like load=4 did).
   RESIDUAL (documented, unmodeled dynamic axis): DMACycleSteal — Beetle adds the live DMA