[FEATURE]: Desktop composer: visible permission-mode control next to the model picker (ask / auto-accept / model-checked)

Problem

In OpenCode Desktop there is no visible, always-accessible permission control anywhere in the session view. Whether the current session will ask for approval or silently auto-accept is not exposed near where you actually work.

This is confirmed in the current source: packages/app/src/components/prompt-input.tsx computes the session's auto-accept state (accepting() memo) but only consumes it internally when submitting a prompt — nothing renders it next to the composer. The only user-facing switch today is a global settings toggle that has repeatedly been reported broken or disabled (#37617, #33788).

For comparison, other agent UIs put this front and center: Codex has a compact permission/mode selector directly next to its model picker, so the agent's autonomy level is always visible and one click away. Claude Code similarly exposes permission modes (plan / accept-edits / auto / bypass), including an LLM-checked auto mode.

Proposal

Add a small permission-mode control to the composer toolbar, next to the model picker, for example segmented options:

• Ask (default — every sensitive tool use prompts)
• Auto-accept (edits and/or commands, scope configurable)
• Model-checked auto (an opt-in classifier reviews calls; unsafe ones fall back to asking — exactly what #37564 proposes)

The state should be per-session, visible at a glance, and switchable mid-session without opening settings.

Relation to existing reports

• #40909 — full /permissions management dialog for per-tool rules; this proposal covers the quick always-visible surface, not the detailed editor
• #37564 — the model-checked auto mode itself
• #41909 — runtime approval toggling as a command
• #38289 — persistent indicator when auto-accept is active; a real inline control would supersede a bare indicator

On enforcement: visible modes are a UX layer only. #2242 tracks the general request for OS-level sandboxing (seatbelt-style, as in Codex); a scoped sandbox would eventually give these modes a hard enforcement backstop instead of relying purely on prompts and rules.

Environment

• App: OpenCode Desktop 1.18.21
• OS: Microsoft Windows 11 Education, 25H2, build 26200.8875