- Theme: added :agent-border, :thinking-bg, :symbolic-border to all 13
presets with theme-load fallback for saved themes.
- Agent output now draws │ with :agent-border color (muted tan).
- Neuro-thinking (streaming): draw-rect at column 0 with :thinking-bg
(dark grey block) instead of a grey │ character. No border text.
- Gate traces: │ with :symbolic-border (was ╎ with :dim).
- Tool calls: │ with tool status color (was ╎).
- Removed > prompt prefix from input line.
- Added position-cursor function: blinking block cursor at insertion
point, called every frame from the main loop after sleep.