Replace the Ink and React terminal UI with an OpenTUI + Solid implementation while preserving Zero's chat/provider flows.
Add a persistent header for provider, model, mode, and usage totals; add an optional todo rail fed by update_plan with Ctrl+T and /todo toggles; add a slash-command popup for /provider, /plan, /todo, /help, and /exit.
Update agent/provider plumbing to surface usage and plan updates, retry OpenAI-compatible streams without stream_options when unsupported, and lazy-load the TUI with the Solid transform for source execution.
Switch the build to a non-exe Bun bundle under dist and remove the old Ink/React dependencies and components.
