Feature: Add "Save Permanently" option to permission prompts #10863

Summary

When a permission prompt appears, add a 4th option to save the approved pattern directly to opencode.json instead of just session memory.

Current Behavior

┌─────────────────────────────────────┐
│ Allow `git status`?                 │
│                                     │
│ [Once]  [Always]  [Reject]          │
└─────────────────────────────────────┘

• Once → Approve this request only
• Always → Approve pattern for this session (lost on restart)
• Reject → Deny

Proposed Behavior

┌─────────────────────────────────────┐
│ Allow `git status`?                 │
│                                     │
│ [Once]  [Session]  [Permanent]  [No]│
└─────────────────────────────────────┘

• Once → Approve this request only
• Session → Approve pattern for this session (current "Always" behavior)
• Permanent → Save pattern to opencode.json (persists across restarts)
• No → Deny

Why This Matters

Currently, users must manually edit opencode.json to add permanent permission patterns:

{
  "permission": {
    "bash": {
      "*": "ask",
      "git status *": "allow"
    }
  }
}

This is tedious and error-prone. The UI already knows the pattern (it shows it during "Always" confirmation) - it just needs to write it to the config file.

Use Case

1. User runs OpenCode with "permission": "ask"
2. Agent tries to run git status
3. User approves with "Permanent"
4. Pattern "git status *": "allow" is appended to opencode.json
5. Next session - no prompt needed for git status

Implementation Notes

• The pattern is already computed (shown in the "Always" confirmation dialog)
• Just needs to append to opencode.json under permission.bash (or relevant tool)
• Should handle nested permission objects gracefully
• Could use jq or native JSON manipulation

Related

• Feature Request: Yolo and non-Yolo mode (auto-accept) #1813 - YOLO mode (all-or-nothing, different use case)
• feat: YOLO Mode - Skip Permission Prompts #9070 - YOLO mode implementation (skip ALL prompts)

This feature is for granular, incremental permission building - not full YOLO mode.