Opencode manual workflow mode is broken

### What happened?

I configured my `opencode.json` as follows:

```
"plugin": [
["@plannotator/opencode@latest", {
"workflow": "manual",
"planningAgents": ["plan"]
}]
]
```
because I don't _always_ want Plannotator to kick in, just when I use `/plannotator-last`.

However, the Plannotator view that shows then only has the "Send Feedback" button. When I press it, Opencode _does edit_ the files immediately, rather than building a new plan!

### Plannotator version

0.27.9

### OS

Linux

### Agent

OpenCode

### Where did it happen?

Plan review

Reproduce the issue using the shown opencode.json configuration, OpenCode, and the /plannotator-last entry point; inspect what happens when Send Feedback is pressed in manual workflow mode. Done means the manual-mode review exposes the intended workflow and feedback does not cause Opencode to edit files immediately instead of building a new plan.

Written by the indexing model from the issue text.