openspec-archive-change

Archive a completed change in the experimental workflow. **Input**: Optionally specify a change name. If omitted, check if it can be inferred from conversation context. If vague or ambiguous you MUST prompt for available changes. **Steps** 1. **If no change name provided, prompt for selection** Run `openspec list --json` to get available changes. Use the **ask the user directly in the conversation** to let the user select. Show only active changes (not already archived). Include the schema used for each change if available. **IMPORTANT**: Do NOT guess or auto-select a change. Always let the user choose. 2. **Check artifact completion status** Run `openspec status --change "<name>" --json` to check artifact completion. Parse the JSON to understand: - `schemaName`: The workflow being used - `artifacts`: List of artifacts with their status (`done` or other) **If any artifacts are not `done`:** - Display warning listing incomplete artifacts - Use **ask the user directly in the conversation** to confirm user wants to proceed - Proceed if user confirms 3. **Check task completion status** Read the tasks file (typically `tasks.md`) to check for incomplete tasks. Count tasks marked with `- [ ]` (incomplete) vs `- [x]` (complete). **If incomplete tasks found:** - Display warning showing count of incomplete tasks - Use **ask the user directly in the conversation** to confirm user wants to proceed - Proceed if user confi...