re: the lookup argument is decoded at 46 of 48 sites -- and it refutes my

own corroboration from last iteration

Last iteration I listed a candidate name vocabulary from "upper-case
strings the callers reference", marked it amber because those are not
proven arguments, and named the check: confirm per call site which string
actually lands in r5. Ran the check. It fired.

The first extractor FAILED ITS OWN CONTROL -- a backward scan for
addi r5 recovered 7 of 48 sites and missed both title sites I had already
read by eye, because there the name is built in r27 and reaches r5 via a
later mr. Rewritten as a forward register simulation it reproduces all
three known sites and recovers 46 of 48, giving 28 distinct names.

Two of my own claims die. DIFFICULTY and EXTRA_MENU are NOT arguments at
any site -- they are strings that merely live in the same functions, so
the "independently corroborated by measurement" line I wrote was an
artifact of the loose filter. Only TUTORIAL_MENU survives. And
sub_821CC860 is not a screen factory at all: its real arguments include
BG, BLACK, FADE, FILE, KEY, PAD, SOUND and GAMMA_RGB. It is a generic
name-keyed lookup, mostly config, which the title part happens to call
with its three state names.

The title finding itself is untouched -- sub_821C6458 really does
transition by calling this with TITLE_SCREEN, TITLE_MENU and LOADING.
What is gone is the inference that the 28 names are a screen vocabulary.

Two METHOD lines, both earned here: strings a function references are not
arguments it passes, and a backward scan for a destination register
misses arguments staged through a scratch register.

docs/re/REFUTED.md

@@ -35,6 +35,13 @@ neighbourhood, not just the line.
 
 ## Screens, classes and RTTI
 
+* "`sub_821CC860` is the game's by-name screen factory" → **mine, and wrong.** Its
+  decoded arguments include `BG`, `BLACK`, `FADE`, `FILE`, `KEY`, `PAD`, `SOUND`,
+  `GAMMA_RGB` — it is a **generic name-keyed lookup**, mostly config.
+* "`DIFFICULTY` and `EXTRA_MENU` are corroborated screen names" → **mine, and
+  wrong.** Neither appears in `r5` at any of the 48 call sites; they were strings
+  merely referenced by the same functions. Only `TUTORIAL_MENU` survives.
+  [`boot-config-and-gamepart-registry.md`](boot-config-and-gamepart-registry.md)
 * "the `{func, func, ptr}` triples at `0x820a3b48` are a GamePart state table" →
   **static-initialiser records trailing the `RegisterToFactory` strings.** The
   bytes before them are the tail of a diagnostic string and the data column is