feat(theme): update Hanmac Green and Brown palette steps

Seven shared Hanmac color tokens change:
- Green Default #123328 -> #164434, Dark 1 #0a221d -> #11372d,
  Dark 2 #071e18 -> #0b2b23, Dark 3 #020a07 -> #030e0a
- Brown Default #3e3523 -> #4e422d, Dark 1 #352d1d -> #403726,
  Dark 3 #1d1810 -> #0d0b07

Updates primitives.css, the generated default values, themes/default.json,
the verification baseline and the hard-coded Default expectations in the
theme Stories and the quality-reference script. --hm-sem-on-accent is
intentionally unchanged. check:theme-defaults reports generated outputs match.

src/theme/verification-baseline.json

@@ -779,13 +779,13 @@
   "--hm-green-light-3": "#249473",
   "--hm-green-light-2": "#266651",
   "--hm-green-light-1": "#205241",
-  "--hm-green-default": "#123328",
-  "--hm-green-dark-1": "#0a221d",
-  "--hm-green-dark-2": "#071e18",
+  "--hm-green-default": "#164434",
+  "--hm-green-dark-1": "#11372d",
+  "--hm-green-dark-2": "#0b2b23",
   "--hm-brown-light-2": "#897445",
   "--hm-brown-light-1": "#604f32",
-  "--hm-brown-default": "#3e3523",
-  "--hm-brown-dark-1": "#352d1d",
+  "--hm-brown-default": "#4e422d",
+  "--hm-brown-dark-1": "#403726",
   "--hm-brown-light-4": "#ecd4a2",
   "--hm-orange-light-4": "#feba88",
   "--hm-orange-default": "#cc5200",