Address PR review feedback (#1461)

- pr-nodes: forward post-increment entity to deps.respond (responseRounds off-by-one); branch-group entity fallback now keys on task.branchContext.groupId, not task.id
- core: hoist shared autoMergeGateReason into @fusion/core pr-entity.ts; CLI + dashboard import the single definition (R13)
- cli: fn pr create also writes the unified PR entity (ensure → open), keeping legacy prInfo; resolveBranchHeadOid uses argv-safe execFileAsync (injection fix)
- changeset: fn-pr-commands bumped minor → major (breaking CLI removal per AGENTS.md)
- tests: bin.test.ts daemon fixture off reserved port 4040; lazy-loaded-views title 19 → 20 views

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

packages/core/src/__tests__/pr-entity.test.ts

@@ -1,5 +1,6 @@
 import { describe, expect, it } from "vitest";
 import {
+  autoMergeGateReason,
   isPrBacked,
   isPrEntityActionable,
   isPrEntityActive,
@@ -71,4 +72,19 @@ describe("PR entity predicates", () => {
     expect(isPrEntityAutoMergeReady({ ...base, mergeable: "unknown" })).toBe(false);
     expect(isPrEntityAutoMergeReady({ ...base, unverified: true })).toBe(false);
   });
+
+  it("autoMergeGateReason is the single R13-shared status string for both surfaces", () => {
+    const ready = entity({
+      autoMerge: true,
+      reviewDecision: "APPROVED",
+      checksRollup: "success",
+      mergeable: "clean",
+    });
+    expect(autoMergeGateReason(ready)).toBe("Ready to merge");
+    expect(autoMergeGateReason({ ...ready, autoMerge: false })).toBe("Auto-merge off");
+    expect(autoMergeGateReason({ ...ready, mergeable: "conflicting" })).toBe("Blocked: conflict");
+    expect(autoMergeGateReason({ ...ready, reviewDecision: "CHANGES_REQUESTED" })).toBe("Waiting for approval");
+    expect(autoMergeGateReason({ ...ready, checksRollup: "pending" })).toBe("Waiting for checks");
+    expect(autoMergeGateReason({ ...ready, mergeable: "unknown" })).toBe("Waiting for checks");
+  });
 });

packages/core/src/index.ts

@@ -611,6 +611,7 @@ export {
   isPrBacked,
   isPrEntityActionable,
   isPrEntityAutoMergeReady,
+  autoMergeGateReason,
 } from "./pr-entity.js";
 export {
   findVitestProcessIds,

packages/core/src/pr-entity.ts

@@ -63,3 +63,21 @@ export function isPrEntityAutoMergeReady(
   if (entity.mergeable !== "clean") return false;
   return true;
 }
+
+/**
+ * The live auto-merge gate reason shown next to the toggle (R11). Mirrors the
+ * auto-merge-ready predicate ordering so every surface (the dashboard route and
+ * the `fn pr` CLI) reports the same status and never disagrees with what the gate
+ * will actually do. Shared in @fusion/core (R13) so the two surfaces cannot drift.
+ */
+export function autoMergeGateReason(
+  entity: Pick<PrEntity, "state" | "unverified" | "autoMerge" | "reviewDecision" | "checksRollup" | "mergeable">,
+): string {
+  if (!entity.autoMerge) return "Auto-merge off";
+  if (entity.mergeable === "conflicting") return "Blocked: conflict";
+  if (entity.reviewDecision !== "APPROVED") return "Waiting for approval";
+  if (entity.checksRollup !== "success") return "Waiting for checks";
+  if (entity.mergeable !== "clean") return "Waiting for checks";
+  if (isPrEntityAutoMergeReady(entity)) return "Ready to merge";
+  return "Waiting for checks";
+}