[BUG]: Desktop: denying a tool permission prompt silently stops the whole agent turn (replacement for stale-closed #30726)

Description

This is a replacement for #30726, which was auto-closed by the stale bot after 60 days of inactivity with an invitation to open a new issue. The behavior is unchanged as far as I can tell in OpenCode Desktop 1.18.21.

In OpenCode Desktop, denying a tool permission prompt silently stops the current agent turn by default.

The prompt reads like the user is rejecting one specific tool call — but the effect is that the whole agent loop ends locally, with no follow-up model request carrying the denied-tool result. To the user it looks like the model or provider stopped mid-task.

Steps to reproduce

1. Run an agent session in OpenCode Desktop on Windows.
2. Let the model request a tool that triggers a permission prompt.
3. Deny the requested tool call.
4. Observe: the denied tool is recorded as a tool error (The user rejected permission to use this specific tool call.), the agent loop stops, and no follow-up request is sent with the denial as context.

Expected behavior

One of:

• Denying a tool permission continues the loop by default and feeds the rejection back to the model so it can take a different approach
• Or Desktop makes the choice explicit with distinct actions such as "Reject and stop" vs. "Reject and continue"
• Or the permission prompt at least surfaces/documents the experimental.continue_loop_on_deny option

The workaround today remains invisible config:

{
  "experimental": {
    "continue_loop_on_deny": true
  }
}

Other agent tools commonly treat a denied call as information for the model ("rejected; try something else"), not as a hidden abort action.

Related context

Since #30726 was filed, this area has seen substantial related activity, which underlines how central predictable permission behavior is: #42436 (permission prompt/deny-rule bypasses), #44246 (keyboard-first permission prompts), #40909 (permissions management UI), plus a cluster of deny-rule matching bugs (#41970, #37935, #35503). Related older reports: #7730, #14297, #9651, #29422.

Environment

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