isl: rename built-ins 8/9/93 to stopwatch_start/_elapsed/_stop

They are start / read / stop of one of 32 per-phase stopwatches, not
flag operations.  123-127 keep timer_* -- that is the mission timer,
five scalars at [phase+304..320], a different clock.

Artefact check: 84 lines changed across 5 files and all 84 pair
exactly with their old-name partners once column padding is
normalised (0 removed lines without an old name, 0 added lines
without a new one).  data/isl-timers.txt reproduces the same
675/675, 11.2 % control, 82/1 and identical histograms, which is
what shows the rename is cosmetic.

Also withdraws a label from the previous commit: sub_8230C398 is NOT
the message pump.  It runs every frame but drains nothing -- a state
machine on [0x828E1F8C] that only allocates, builds strings, looks up
and PUSHES.  And bus+8216 is weak evidence: sub_82254A08 is a generic
map find with ~120 sites, and the key looked up is a pointer, not a
tag.  The open handle is now the ring buffer at bus+4, not bus+8216.

docs/re/structures/isl-mission-timer.md

@@ -145,11 +145,27 @@ no table of subscribed tags to find either.
 ### 🟡 Where the subscriber actually lives — located, not read
 
 The bus object at `[0x828F35DC]` carries a **map at `+8216`**, looked up through
-`sub_82254A08` from **`sub_823001E8`** — whose only caller is `sub_8230C398`, the
-per-frame message pump (itself called from the frame loop `sub_821A6544` with the
-frame `dt`). So dispatch is a **runtime registry keyed by the tag**, and the
-question "does running out of time end the mission" reduces to: *what inserts into
-`bus+8216`, and with which key.* That insert path is not read here.
+`sub_82254A08` from **`sub_823001E8`** — whose only caller is `sub_8230C398`.
+
+🔴 **Correction to my own label from the previous pass.** I called
+`sub_8230C398` "the per-frame message pump". It is *called* every frame (from
+`sub_821A6470` at `0x821A654C` and from the mission loop `sub_821AA1B0` at
+`0x821AA7DC`, both with the frame `dt`), but **it drains nothing**: its whole
+body is a state machine on the counter at `[0x828E1F8C]`, and across 466
+instructions it calls only an allocator (`sub_8230C160`), string building
+(`sub_8217FA08`), a map lookup (`sub_823001E8`) and a *push* (`sub_8225FEA0`).
+It is a boot/loading sequencer that posts messages, not the consumer of them.
+
+Two further cautions the search turned up:
+
+* `sub_82254A08` is a **generic map find** with ~120 call sites image-wide, and
+  `+8216` is a common offset — the pair alone identifies nothing.
+* The key `sub_823001E8` looks up is a **pointer** (`lwz r4, 13780(r11)` stored
+  and passed by address), **not a message tag**. So `bus+8216` may not be the
+  subscriber registry at all.
+
+**So the drain of the queue at `bus+4` is still unlocated**, and with it the
+answer to whether running out of time ends the mission.
 
 ## 🟡 Not settled
 

docs/re/structures/isl-timers.md

@@ -109,13 +109,16 @@ in a coherent block of stages) — checked before believing.
 
 ## 🟡 What this leaves
 
-* The **naming**. `set_flag` / `read_freg` / `clear_flag` describe none of this.
-  ✅ The other timer is now read — [isl-mission-timer](isl-mission-timer.md) —
-  so the collision is understood: 123/124/125/126/127 act on five *scalar*
-  fields (`[phase+304…320]`), this family on a 32-entry *bank*. `stopwatch_start`
-  / `stopwatch_elapsed` / `stopwatch_stop` would separate them. Still not renamed
-  here, so every artefact regenerates byte-identical; the rename is its own
-  change and its own artefact diff.
+* ~~The **naming**.~~ ✅ **RENAMED (2026-08-27).** `isl.py` now emits
+  **`stopwatch_start` (8) / `stopwatch_elapsed` (9) / `stopwatch_stop` (93)**;
+  built-ins 123–127 keep `timer_*` for the *other* clock
+  ([isl-mission-timer](isl-mission-timer.md)), which acts on five scalar fields
+  rather than a 32-entry bank. The rename touched **84 lines across 5 artefacts
+  and every one pairs exactly** with its old-name partner once column padding is
+  normalised — nothing but the three names changed, and this file's own artefact
+  reproduces the same 675/675, 11.2 %, 82/1 numbers under the new labels.
+  ⚠️ Older prose in the corpus still uses the old names where it is quoting what
+  was believed at the time; that is deliberate.
 * The **one exception**: `read_freg(15)` in Stage 06 phase 1 is not started by a
   `set_flag(15)` in that phase. Cross-phase carry-over or a start in the
   unreached code — not chased.