fix: make join review read only

docs/superpowers/plans/2026-07-14-workflow-ui-regressions.md

@@ -104,20 +104,20 @@ Expected: PASS.
 - Consumes: options `{ id, label, detail?, rationale? }`.
 - Produces: response `{ id, kind: "join-review", choices: allOptionIds }` on `Continue`.
 
-- [ ] **Step 1: Write failing builder and gate tests**
+- [x] **Step 1: Write failing builder and gate tests**
 
 Assert the builder emits read-only option details, `confirm_label: "Continue"`, and reserved controls.
 Exercise `reviewer_decide` with only `join_modified` decisions; queue a Continue response containing
 all ids and assert every `tht decision add` call occurs. Queue `control:"freetext"` and assert no
 decision is written.
 
-- [ ] **Step 2: Run harness tests and verify RED**
+- [x] **Step 2: Run harness tests and verify RED**
 
 Run: `cd harness && node --test .pi/extensions/gate/__tests__/builders.test.js .pi/extensions/gate/__tests__/gate_join_review.test.js`
 
 Expected: builder/export/widget contract is missing and join calls still emit `multiselect`.
 
-- [ ] **Step 3: Implement builder and gate routing**
+- [x] **Step 3: Implement builder and gate routing**
 
 Add `buildJoinReviewRequest`. In `reviewer_decide`, detect a non-empty, join-only merit list:
 
@@ -128,24 +128,24 @@ const joinOnly = opts.length > 0 && opts.every((o) => o.decision.type === "join_
 Emit `join-review` with `detail` and `rationale`; after Continue persist all original decisions.
 On free text, return feedback without persistence. Keep all other decisions on `multiselect`.
 
-- [ ] **Step 4: Write failing frontend widget tests**
+- [x] **Step 4: Write failing frontend widget tests**
 
 Render two join cards and assert there are no checkboxes. Click `Continue` and expect all ids in the
 response. Open `Other — specify`, submit correction text, and expect a freetext control response.
 
-- [ ] **Step 5: Run frontend widget tests and verify RED**
+- [x] **Step 5: Run frontend widget tests and verify RED**
 
 Run: `cd frontend && npx vitest run src/widgets/JoinReviewWidget.test.tsx src/widgets/registry.test.tsx`
 
 Expected: widget and registry entry are missing.
 
-- [ ] **Step 6: Implement and register JoinReviewWidget**
+- [x] **Step 6: Implement and register JoinReviewWidget**
 
 Render semantic cards with label, detail, and rationale, one `Continue` primary button, and
 `ReservedControls`. Register `join-review` and extend `WidgetOption` with optional `detail` and
 `rationale` strings.
 
-- [ ] **Step 7: Update model instructions and verify targeted tests**
+- [x] **Step 7: Update model instructions and verify targeted tests**
 
 Document that joins must be a separate join-only `reviewer_decide` call; the reviewer cannot remove
 individual joins and textual corrections require a complete revised proposal.