feat(console): persist accent toggle + add monochrome-text toggle

Persist the two console output display preferences and add a second toolbar
toggle for monochrome text.

- Persistence: new Settings fields console_line_accents / console_text_color
  (both default true, matching the ConsoleTab statics so an upgrade re-save
  can't flip visible behavior). Restored into the statics at startup in the App
  constructor, and saved from a diff-and-save after the console renders (only
  when a value actually changed — save() is disk I/O). The startup restore also
  fixes a pre-existing bug: scanline was only synced from settings when the
  Settings page or first-run wizard ran, so an existing wallet ignored a saved
  scanline preference on launch.
- Monochrome text: a new toolbar toggle (FORMAT_COLOR_TEXT, dimmed when off)
  next to the accent toggle. channelTextColor() early-returns the neutral
  COLOR_RESULT for every channel (and JSON syntax role) when off, leaving the
  left accent bars independent. COLOR_RESULT is contrast-floored per theme, so
  text stays readable on light and dark terminals.

Adds console_toggle_text_color to the English source + all 8 translations.
Verified: both toggles independent, persistence round-trips across restart,
monochrome readable on light + dark skins.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/ui/windows/console_tab.h

@@ -72,6 +72,9 @@ public:
     // Draw the per-line left color accent bars (channel-colored). Toggled from the toolbar.
     static bool s_line_accents_enabled;
 
+    // Color output text per channel. When false the console is monochrome text. Toolbar-toggled.
+    static bool s_line_text_color_enabled;
+
     // Show/hide daemon output messages
     static bool s_daemon_messages_enabled;