feat(terminal): Kitty only — drop Ghostty (#95)

Ghostty's OpenGL 4.3 floor broke the Acer (HD 4000 / 4.2). Dual-terminal
support (default Ghostty + install-time Kitty fallback) was more complexity
than it was worth.

- Remove ghostty.nix / nomarchy.ghostty.enable
- Kitty always installed and themed from theme-state
- Default nomarchy.terminal = kitty; SUPER+Return, doctor, calendar,
  what-changed use kitty --class=com.nomarchy.*
- Drop install-time glxinfo probe and mesa-demos on the installer
- Docs/REQUIREMENTS no longer list OpenGL 4.3 as a terminal floor

Verified: V0 flake check; option-docs; installer-safety; template HM has
kitty, no ghostty; menu/calendar emit classed kitty launches.

agent/JOURNAL.md

@@ -19,7 +19,19 @@ Template:
 
 ---
 
-## 2026-07-15 — #95: themed Kitty when OpenGL < 4.3 (this commit)
+## 2026-07-15 — #95 complete: Kitty is the only terminal (this commit)
+- **Task:** Bernardo: make kitty default and only option — drop dual-terminal
+  complexity (Ghostty failed on Acer OpenGL 4.2; fallback was more code).
+- **Did:** Removed `ghostty.nix` and `nomarchy.ghostty.enable`. Kitty always
+  installed + themed; default `nomarchy.terminal = "kitty"`. Doctor, calendar,
+  what-changed → `kitty --class=com.nomarchy.*`. Dropped install-time GL
+  probe + mesa-demos. Updated README/REQUIREMENTS/OVERRIDES/TESTING/tools.
+- **Verified:** V0 flake check; downstream-template-home builds with kitty,
+  no ghostty; installer-safety green.
+- **Pending:** V3 Acer SUPER+Return + doctor float (HARDWARE-QUEUE).
+- **Next suggestion:** #123 (HM pre-activate dconf).
+
+## 2026-07-15 — #95: themed Kitty when OpenGL < 4.3 (superseded above)
 - **Task:** Bernardo: when GL &lt; 4.3 automatically add kitty — and theme it.
 - **Did:** `modules/home/kitty.nix` themes Kitty from theme-state (same
   palette/font/opacity as Ghostty); enables when `nomarchy.terminal` is