feat(pi): first-class support via pi-subagents + pi-ask-user (#651)

Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

plugins/compound-engineering/skills/ce-compound-refresh/SKILL.md

@@ -31,7 +31,7 @@ Check if `$ARGUMENTS` contains `mode:autofix`. If present, strip it from argumen
 
 Follow the same interaction style as `ce-brainstorm`:
 
-- Ask questions **one at a time** — use the platform's blocking question tool: `AskUserQuestion` in Claude Code (call `ToolSearch` with `select:AskUserQuestion` first if its schema isn't loaded), `request_user_input` in Codex, `ask_user` in Gemini. Fall back to numbered options in plain text only when no blocking tool exists in the harness or the call errors (e.g., Codex edit modes) — not because a schema load is required. Never silently skip the question
+- Ask questions **one at a time** — use the platform's blocking question tool: `AskUserQuestion` in Claude Code (call `ToolSearch` with `select:AskUserQuestion` first if its schema isn't loaded), `request_user_input` in Codex, `ask_user` in Gemini, `ask_user` in Pi (requires the `pi-ask-user` extension). Fall back to numbered options in plain text only when no blocking tool exists in the harness or the call errors (e.g., Codex edit modes) — not because a schema load is required. Never silently skip the question
 - Prefer **multiple choice** when natural options exist
 - Start with **scope and intent**, then narrow only when needed
 - Do **not** ask the user to make decisions before you have evidence
@@ -393,7 +393,7 @@ Do **not** ask questions about whether code changes were intentional, whether th
 
 #### Question Style
 
-Always present choices using the platform's blocking question tool: `AskUserQuestion` in Claude Code (call `ToolSearch` with `select:AskUserQuestion` first if its schema isn't loaded), `request_user_input` in Codex, `ask_user` in Gemini. Fall back to numbered options in plain text only when no blocking tool exists in the harness or the call errors (e.g., Codex edit modes) — not because a schema load is required. Never silently skip the question.
+Always present choices using the platform's blocking question tool: `AskUserQuestion` in Claude Code (call `ToolSearch` with `select:AskUserQuestion` first if its schema isn't loaded), `request_user_input` in Codex, `ask_user` in Gemini, `ask_user` in Pi (requires the `pi-ask-user` extension). Fall back to numbered options in plain text only when no blocking tool exists in the harness or the call errors (e.g., Codex edit modes) — not because a schema load is required. Never silently skip the question.
 
 Question rules:
 
@@ -673,6 +673,6 @@ After the refresh report is generated, check whether the project's instruction f
 
       `docs/solutions/` — documented solutions to past problems (bugs, best practices, workflow patterns), organized by category with YAML frontmatter (`module`, `tags`, `problem_type`). Relevant when implementing or debugging in documented areas.
       ```
-   c. In interactive mode, explain to the user why this matters — agents working in this repo (including fresh sessions, other tools, or collaborators without the plugin) won't know to check `docs/solutions/` unless the instruction file surfaces it. Show the proposed change and where it would go, then use the platform's blocking question tool to get consent before making the edit: `AskUserQuestion` in Claude Code (call `ToolSearch` with `select:AskUserQuestion` first if its schema isn't loaded), `request_user_input` in Codex, `ask_user` in Gemini. Fall back to presenting the proposal in chat only when no blocking tool exists in the harness or the call errors (e.g., Codex edit modes) — not because a schema load is required. Never silently skip the question. In autofix mode, include it as a "Discoverability recommendation" line in the report — do not attempt to edit instruction files (autofix scope is doc maintenance, not project config).
+   c. In interactive mode, explain to the user why this matters — agents working in this repo (including fresh sessions, other tools, or collaborators without the plugin) won't know to check `docs/solutions/` unless the instruction file surfaces it. Show the proposed change and where it would go, then use the platform's blocking question tool to get consent before making the edit: `AskUserQuestion` in Claude Code (call `ToolSearch` with `select:AskUserQuestion` first if its schema isn't loaded), `request_user_input` in Codex, `ask_user` in Gemini, `ask_user` in Pi (requires the `pi-ask-user` extension). Fall back to presenting the proposal in chat only when no blocking tool exists in the harness or the call errors (e.g., Codex edit modes) — not because a schema load is required. Never silently skip the question. In autofix mode, include it as a "Discoverability recommendation" line in the report — do not attempt to edit instruction files (autofix scope is doc maintenance, not project config).
 
 5. **Amend or create a follow-up commit when the check produces edits.** If step 4 resulted in an edit to an instruction file and Phase 5 already committed the refresh changes, stage the newly edited file and either amend the existing commit (if still on the same branch and no push has occurred) or create a small follow-up commit (e.g., `docs: add docs/solutions/ discoverability to AGENTS.md`). If Phase 5 already pushed the branch to a remote (e.g., the branch+PR path), push the follow-up commit as well so the open PR includes the discoverability change. This keeps the working tree clean and the remote in sync at the end of the run. If the user chose "Don't commit" in Phase 5, leave the instruction-file edit unstaged alongside the other uncommitted refresh changes — no separate commit logic needed.