re: r0 is not a base register - the last shortlisted row withdrawn

sub_825F2CF0 / sub_825F2F88 (r0, 30 names each, 97% disc names) are not
name-block readers at all: they are the compiler's VMX save/restore helper
pair. 145 instructions each, 72 differ, every difference stvx<->lvx over
v14..v127.

Root cause: in `addi rD, rA, N` the rA slot reads as literal zero when it
names r0, so `addi r11, r0, -N` is `li r11, -N` - vector spill offsets, not
displacements. The solver excluded r1 only; the bogus base landed inside the
stage-settings name block, dense enough to "resolve" 30 real field names.

name_block_bases.py now skips r0 as well. Rows 277 -> 261, functions 190 ->
176, non-64K bases 170 -> 154, data-table rows 53 -> 50; 154+107=261 and
277-16=261. Artefact diff -100/+3, every removed row line carries r0, control
sub_82341A20 r30 = 0x82088F94 217/226 untouched.

Nothing lost: all 30 names are a strict subset of sub_8230D1F8 r29 (129
names), the stage-settings loader already in the corpus. String-xref join
agrees - FinalPassBG, FogMinDistance, ScreenColorR, ExposureKey_BeginValue
each exist once with exactly one xref, from sub_8230D1F8.

Fourteen other artefacts byte-identical; name-block-bases.txt byte-identical
on a second run.

tools/re-capture/name_block_bases.py

@@ -57,7 +57,13 @@ def main():
     for name in sorted(byf):
         for reg in sorted(byf[name]):
             D = sorted(set(byf[name][reg]))
-            if len(D) < MIN_GROUP or reg == 'r1':      # r1 is the stack pointer
+            # r1 is the stack pointer.  r0 is NOT a base register at all: in
+            # `addi rD, r0, N` the RA slot reads as literal zero, so the form is
+            # `li rD, N` and the displacements are plain immediates.  Left in, the
+            # VMX save/restore helper pair sub_825F2CF0 / sub_825F2F88 (72 x
+            # `addi r11, r0, -N`, the vector spill offsets) solved a base and
+            # "named" 30 strings, 97% of them disc names -- a pure artefact.
+            if len(D) < MIN_GROUP or reg in ('r0', 'r1'):
                 continue
             # Vote: every (string, displacement) pair implies one candidate base.
             # The true base collects a vote from each name it explains, so it wins