feat(matlab): windowed paper-LME replication for mergeNaive (d0_10, d0_13)

Make tdcs_paper_lme window-aware (windowKey 'full'|'d0_10'|'d0_13',
default 'full' -> unchanged filename). Windowed runs give the two anchor
arms equal day coverage, so the stim:day interaction is not confounded by
the full-range coverage imbalance; the report now states whether coverage
is equal and adds an INTERPRETATION block. Add switch cases
paper_mergeNaive_d0_10 / _d0_13 and include them in run_all.

Finding: unlike mergeA2 (fair-window interaction n.s.), the pooled-naive
control keeps the interaction significant in the fair d0_13 window
(F(1)=7.07, p=0.0088, +1.80 [+0.46,+3.14]; equal on Day 1 p=0.20),
reproducing the paper without the coverage confound; d0_10 is borderline
(p=0.051).

Tests: tLme asserts equal coverage / no warning / one full summary for
both windows and a significant positive d0_13 interaction; bad windowKey
errors. Suite 41/41.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

analysis/matlab/tdcs_glm.m

@@ -136,6 +136,12 @@ switch scenario
     case 'paper_mergeNaive'
         tdcs_paper_lme('mergeNaive', cfg);
 
+    case 'paper_mergeNaive_d0_10'
+        tdcs_paper_lme('mergeNaive', cfg, 'd0_10');
+
+    case 'paper_mergeNaive_d0_13'
+        tdcs_paper_lme('mergeNaive', cfg, 'd0_13');
+
     case 'phase_mergeNaive'
         tdcs_phase_lme('mergeNaive', cfg);