Re-add Architect Mode / Enhance Plan Mode to Write Plan Files

Priority: P2 Status: ❌ Not started Issue: #6230

Problem

The old Kilo Code extension had an "Architect mode" that would write the resulting plan as a .md file into a /plans directory in the project root. Users adopted this workflow and now miss it.

The new extension has Plan mode, but plans are stored only inside .opencode/ — not as human-readable .md files in the project. Users can't see or reference their plans easily.

Remaining Work

Options (pick one or combine):

1. Enhance Plan mode — After a plan is finalized, automatically write it as a .md file to a /plans directory in the project root. The filename could be based on the plan title or a timestamp. This happens in addition to the internal .opencode/ storage.

2. Re-add Architect mode — Add a distinct "Architect" mode that is specifically focused on writing plans as .md files to /plans.

3. Prompt Plan mode — When finishing a plan, offer the user a choice: "Save plan to /plans/plan-name.md?" with accept/dismiss.

Option 3 is the least disruptive. The recommended approach is to add an "Export plan" action button in the Plan mode UI that saves the current plan to /plans/.

Implementation Notes

• This requires CLI-side changes to the Plan mode behavior and/or an extension-side "export plan" button
• The plan content is available in the session; extracting it requires identifying what parts constitute the plan output
• /plans/ directory creation should be done safely (don't overwrite existing files without confirmation)