Docs audit: nine stale class-ID counts left behind by the terminator fix

Checked the docs for claims this session retracted. Found a real one: the vtbl
terminator fix (cc52060) corrected the distinct class-id count from 1,163 to 1,162,
and nine places in the format spec and two in the roadmap still said 1,163.

    docs/formats/core-data-regions.md   9 occurrences
    docs/roadmap.md                     2 occurrences

The reason they survived is the same shape as the vtbl bug itself. The test was
fixed and the new number asserted, but the prose kept the old one, and the prose is
what a reader takes away. A commit that corrects a measurement and does not correct
the document it was measured in has only half-landed.

Checked the numerators before touching them rather than blanket-replacing: 1,135 of
the ids are at or above level 0's moby_classes.count, and 1,133 are at or above the
largest per-level table. Both were already correct -- only the denominators were
wrong -- so a find-and-replace across the number would have corrupted two correct
figures. The tests confirm:

    lvl.vtbl: 1162 distinct class ids from 5822 records; max 0x13ba (5050);
    moby_classes.count is 238, and 1135 of 1162 ids (97.7%) are at or above it

Left one deliberate occurrence of "1,163" in the spec, in a note explaining that the
figure was 1,163 until the terminator fix and why, so the correction is traceable
rather than looking like a typo.

293 passing with the disc and savestate present, clippy clean. Documentation only.

docs/roadmap.md

@@ -421,7 +421,7 @@ Phase 1 hands over the extents; this phase works out what each one contains.
       Vertices are 16-byte VIF-packed half-float quads, handed back raw.
 - [x] The **moby class-id space is known**: `lvl.vtbl` (section 3 of the level
       program) is records of `{oClass, handler, auxiliary}`, and across 27 levels
-      that is **1,163 distinct ids** reaching `0x13BA` (5,050), median 38 new per
+      that is **1,162 distinct ids** reaching `0x13BA` (5,050), median 38 new per
       level. `moby_classes.count` is 238 and **97.6% of real ids are at or above
       it**, so the count was never a valid bound -- which is the mechanism behind
       the chunk class-ID artifact now retracted. Re-scored against the real set,
@@ -441,7 +441,7 @@ Phase 1 hands over the extents; this phase works out what each one contains.
       across levels rather than renumbered. Handler addresses are function
       entries in the same overlay's `.text`, which is now readable. Asserted.
 - [x] `lvl.vtbl`'s **`oClass` is a global identifier**, not an index into the level's
-      class table: 1,163 distinct ids across the game, largest 5,050, against
+      class table: 1,162 distinct ids across the game, largest 5,050, against
       `moby_classes.count` of 136..259. **1,133 of 1,163 are out of range** for any
       per-level table. The two are different axes -- a type id, and the models a
       level instantiates -- and the space is shared rather than renumbered