Set Openspec Path

Update openspecPath in .claude/project-context.json so the SessionStart hook injects the chosen project's openspec docs folder. This replaces hand-editing the absolute path with a menu choice.

Steps:

1. Read .claude/project-context.json from the current project root.

   • If the file does not exist, tell the user to run setup-project-context first and stop.
   • If it cannot be parsed as JSON, show the parse error and stop.

2. Collect the projects array (entries with a non-empty path). Present the choices to the user with AskUserQuestion:

   • One option per registered project, labelled by name (falling back to path), with the resulting <path>/openspec shown in the description.
   • Plus a "Clear (use working-dir openspec)" option that sets openspecPath to "" — the hook then falls back to <project-root>/openspec automatically.
   • If projects is empty, tell the user there are no registered projects to pick from and stop.

3. Write the result back into .claude/project-context.json:

   • For a project choice, set openspecPath to <chosen project path>/openspec (forward slashes, no trailing slash).
   • For "Clear", set openspecPath to "".
   • Preserve every other field (roleBasedDelegation, projects, ordering, formatting) unchanged — only the openspecPath value is modified.

4. Report the new openspecPath value and remind the user:

   • The change takes effect on the next session start — /reload-plugins does not re-run SessionStart, so start a new session or /clear.
   • If the chosen project has no openspec folder, the hook automatically falls back to the working-directory openspec at injection time.