fix(theme): dark adw-gtk3 for dark palettes — GTK dialog buttons (#98)

Stylix always used the light adw-gtk3 sheet with recolored tokens; that
sheet hardcodes near-black button labels, which became black-on-dark in
Boreal GTK dialogs. Force adw-gtk3-dark (and prefer-dark) for dark mode,
and pin dialog button label colours in Stylix extraCss.

agent/JOURNAL.md

@@ -19,6 +19,17 @@ Template:
 
 ---
 
+## 2026-07-15 — #98 GTK dialog button black-on-dark (Boreal)
+- **Task:** Bernardo: GTK dialog button labels black vs dark Boreal chrome.
+- **Did:** Root cause — Stylix pins light `adw-gtk3` for all polarities.
+  Force `adw-gtk3-dark` when mode=dark, prefer-dark, and extraCss for
+  dialog/action button labels (suggested/destructive keep dark-on-pastel).
+- **Verified:** V1 HM gen: settings.ini `gtk-theme-name=adw-gtk3-dark`,
+  prefer-dark=true, gtk.css button rules present. V3: open a GTK dialog
+  after nomarchy-home.
+- **Pending:** V3 eyeball on real session.
+- **Next suggestion:** hardware queue or human #115/#120.
+
 ## 2026-07-15 — Document generation prune for users (#128 docs)
 - **Task:** User-facing docs for the 14d / keep-≥3-past policy.
 - **Did:** RECOVERY §4 (how gens are kept); README generation section +