openspec-verify-change

Verify that an implementation matches the change artifacts (specs, tasks, design). **Store selection:** If the user names a store (a store is a standalone OpenSpec repo registered on this machine) or the work lives in one, run `openspec store list --json` to discover registered store ids, then pass `--store <id>` on the commands that read or write specs and changes (`new change`, `status`, `instructions`, `list`, `show`, `validate`, `archive`, `doctor`, `context`, `view`). Other commands do not take the flag. Hints printed by commands already carry the flag; keep it on follow-ups. Without a store, commands act on the nearest local `openspec/` root. **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. **Select the change** If a name is provided, use it. Otherwise: - Infer from conversation context if the user mentioned a change - Auto-select if only one active change exists - If ambiguous, run `openspec list --json` to get available changes and ask the user to select one When prompting, show changes that have implementation tasks (tasks artifact exists). Include the schema used for each change if available. Mark changes with incomplete tasks as "(In Progress)". Always announce: "Using change: <name>" and how to override (e.g., `/openspec-verify-change <other>`). 2. **Check status to understand the schema** ```ba...