feat: align terminal font settings with appearance fonts

- Terminal font dropdown now uses mono fonts from UI font options
- Unified font list between appearance section and terminal settings
- Terminal font persisted to GlobalSettings for import/export support
- Aligned global terminal settings popover with per-terminal popover:
  - Same settings in same order (Font Size, Run on New Terminal, Font Family, Scrollback, Line Height, Screen Reader)
  - Consistent styling (Radix Select instead of native select)
- Added terminal padding (12px vertical, 16px horizontal) for readability

libs/types/src/settings.ts

@@ -472,6 +472,8 @@ export interface GlobalSettings {
   fontFamilySans?: string;
   /** Global Code/Mono font family (undefined = use default Geist Mono) */
   fontFamilyMono?: string;
+  /** Terminal font family (undefined = use default Menlo/Monaco) */
+  terminalFontFamily?: string;
 
   // UI State Preferences
   /** Whether sidebar is currently open */