analysis(matlab): per-variation subfolders (grouping x window) for the paper LME

Add make_variations.m + variation_analyze.m generating 20 self-contained
subfolders under analysis/matlab/variations/, one per grouping x day-window,
each with exactly three files: data.csv (curated subset), analyze.m (a simple
standalone script fitting behavior ~ stim + day + stim:day + (1|rat) on the
success COUNT), and result.txt (its output). Plus variations/SUMMARY.csv.

Groupings (stim=1 / stim=0, other groups dropped):
  unmerge     B2 vs A2
  right_only  B2+Right vs A2            (Box-A dropped)
  naive_a2    B2 vs A2+Naive           (Right, Box-A dropped)
  naive_boxa  B2 vs A2+Naive+Box-A     (Right dropped)
Windows: 0-10, 0-13, 0-5, 6-10, 6-13. All 20 have equal day coverage.

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

analysis/matlab/variations/naive_boxa_d6_13/data.csv

@@ -0,0 +1,74 @@
+subject,group,day,success,total,stim
+Banh-mi-1,Electrode-Box-B2,6,90,131,1
+Banh-mi-1,Electrode-Box-B2,7,109,148,1
+Banh-mi-1,Electrode-Box-B2,8,104,137,1
+Banh-mi-1,Electrode-Box-B2,9,119,150,1
+Banh-mi-1,Electrode-Box-B2,10,121,158,1
+Banh-mi-1,Electrode-Box-B2,11,121,148,1
+Banh-mi-1,Electrode-Box-B2,12,120,149,1
+Banh-mi-1,Electrode-Box-B2,13,135,154,1
+Banh-mi-2,Electrode-Box-A2,6,74,146,0
+Banh-mi-2,Electrode-Box-A2,7,70,148,0
+Banh-mi-2,Electrode-Box-A2,8,65,130,0
+Banh-mi-2,Electrode-Box-A2,9,79,151,0
+Banh-mi-2,Electrode-Box-A2,10,93,152,0
+Egg-tart-1,Electrode-Box-B2,6,71,142,1
+Egg-tart-1,Electrode-Box-B2,7,79,138,1
+Egg-tart-1,Electrode-Box-B2,8,98,142,1
+Egg-tart-1,Electrode-Box-B2,9,89,139,1
+Egg-tart-1,Electrode-Box-B2,10,96,143,1
+Egg-tart-1,Electrode-Box-B2,11,96,148,1
+Egg-tart-1,Electrode-Box-B2,12,101,156,1
+Egg-tart-1,Electrode-Box-B2,13,103,152,1
+Egg-tart-2,Electrode-Box-A2,6,85,145,0
+Egg-tart-2,Electrode-Box-A2,7,79,143,0
+Egg-tart-2,Electrode-Box-A2,8,76,131,0
+Egg-tart-2,Electrode-Box-A2,9,88,149,0
+Egg-tart-2,Electrode-Box-A2,10,81,151,0
+Egg-tart-2,Electrode-Box-A2,11,78,152,0
+Egg-tart-2,Electrode-Box-A2,12,96,155,0
+Egg-tart-2,Electrode-Box-A2,13,84,155,0
+Khoai-lang-2,Naive,6,21,72,0
+Khoai-lang-2,Naive,7,23,99,0
+Khoai-lang-2,Naive,8,64,136,0
+Khoai-lang-2,Naive,9,75,131,0
+Khoai-lang-2,Naive,10,63,134,0
+Khoai-lang-2,Naive,11,59,139,0
+Khoai-lang-2,Naive,12,51,129,0
+Khoai-lang-2,Naive,13,73,143,0
+Khoai-tay-1,Electrode-Box-A,6,81,137,0
+Khoai-tay-1,Electrode-Box-A,7,78,147,0
+Khoai-tay-1,Electrode-Box-A,8,91,132,0
+Khoai-tay-1,Electrode-Box-A,9,99,146,0
+Khoai-tay-1,Electrode-Box-A,10,94,143,0
+Khoai-tay-1,Electrode-Box-A,11,110,156,0
+Khoai-tay-1,Electrode-Box-A,12,105,143,0
+Khoai-tay-1,Electrode-Box-A,13,106,153,0
+Khoai-tay-2,Naive,6,62,144,0
+Khoai-tay-2,Naive,7,87,141,0
+Khoai-tay-2,Naive,8,105,152,0
+Khoai-tay-2,Naive,9,75,148,0
+Khoai-tay-2,Naive,10,101,149,0
+Khoai-tay-2,Naive,11,102,154,0
+Khoai-tay-2,Naive,12,95,144,0
+Khoai-tay-2,Naive,13,77,149,0
+OM-2,Naive,6,73,138,0
+OM-2,Naive,7,80,131,0
+OM-2,Naive,8,91,141,0
+OM-2,Naive,9,90,135,0
+OM-2,Naive,10,95,142,0
+OM-2,Naive,11,60,133,0
+OM-2,Naive,12,58,142,0
+Root-beer-1,Electrode-Box-B2,6,104,139,1
+Root-beer-1,Electrode-Box-B2,7,98,148,1
+Root-beer-1,Electrode-Box-B2,8,81,145,1
+Root-beer-1,Electrode-Box-B2,9,89,156,1
+Root-beer-1,Electrode-Box-B2,10,105,158,1
+Vu-vuong,Naive,6,49,131,0
+Vu-vuong,Naive,7,65,149,0
+Vu-vuong,Naive,8,67,141,0
+Vu-vuong,Naive,9,73,140,0
+Vu-vuong,Naive,10,72,131,0
+Vu-vuong,Naive,11,89,158,0
+Vu-vuong,Naive,12,97,154,0
+Vu-vuong,Naive,13,93,145,0