fix(gsd): use project root for prior-slice dispatch guard (#2863)

Resolve the prior-slice completion guard against originalBasePath when auto-mode is running in a worktree. This keeps completed upstream milestones from blocking new dispatches because their SUMMARY state lives at the project root, not the stale worktree snapshot.

Closes #2838

Co-authored-by: Paperclip <noreply@paperclip.ing>

src/resources/extensions/gsd/auto/phases.ts

@@ -45,6 +45,17 @@ export function _resolveReportBasePath(s: Pick<AutoSession, "originalBasePath" |
   return s.originalBasePath || s.basePath;
 }
 
+/**
+ * Resolve the authoritative project base for dispatch guards.
+ * Prior-milestone completion lives at the project root, even when the active
+ * unit is running inside an auto worktree.
+ */
+export function _resolveDispatchGuardBasePath(
+  s: Pick<AutoSession, "originalBasePath" | "basePath">,
+): string {
+  return s.originalBasePath || s.basePath;
+}
+
 /**
  * Generate and write an HTML milestone report snapshot.
  * Extracted from the milestone-transition block in autoLoop.
@@ -667,9 +678,10 @@ export async function runDispatch(
     prompt = preDispatchResult.prompt;
   }
 
+  const guardBasePath = _resolveDispatchGuardBasePath(s);
   const priorSliceBlocker = deps.getPriorSliceCompletionBlocker(
-    s.basePath,
-    deps.getMainBranch(s.basePath),
+    guardBasePath,
+    deps.getMainBranch(guardBasePath),
     unitType,
     unitId,
   );

src/resources/extensions/gsd/tests/journal-integration.test.ts

@@ -260,6 +260,61 @@ test("runDispatch emits dispatch-stop when dispatch returns stop action", async
   assert.equal(stopEvents[0].flowId, ic.flowId);
 });
 
+test("runDispatch checks prior-slice completion against the project root in worktree mode", async () => {
+  const capture = createEventCapture();
+  const guardCalls: Array<{ fn: string; args: unknown[] }> = [];
+  const deps = makeMockDeps(capture, {
+    getMainBranch: (basePath: string) => {
+      guardCalls.push({ fn: "getMainBranch", args: [basePath] });
+      return "main";
+    },
+    getPriorSliceCompletionBlocker: (
+      basePath: string,
+      mainBranch: string,
+      unitType: string,
+      unitId: string,
+    ) => {
+      guardCalls.push({
+        fn: "getPriorSliceCompletionBlocker",
+        args: [basePath, mainBranch, unitType, unitId],
+      });
+      return null;
+    },
+  });
+  const ic = makeIC(deps, {
+    s: {
+      ...makeSession(),
+      basePath: "/tmp/project/.gsd/worktrees/M029-xoklo9",
+      originalBasePath: "/tmp/project",
+    } as any,
+  });
+  const preData: PreDispatchData = {
+    state: {
+      phase: "executing",
+      activeMilestone: { id: "M029-xoklo9", title: "Test", status: "active" },
+      activeSlice: { id: "S01", title: "Slice 1" },
+      registry: [{ id: "M029-xoklo9", status: "active" }],
+      blockers: [],
+    } as any,
+    mid: "M029-xoklo9",
+    midTitle: "Test Milestone",
+  };
+
+  const result = await runDispatch(ic, preData, {
+    recentUnits: [],
+    stuckRecoveryAttempts: 0,
+  });
+
+  assert.equal(result.action, "next");
+  assert.deepEqual(guardCalls, [
+    { fn: "getMainBranch", args: ["/tmp/project"] },
+    {
+      fn: "getPriorSliceCompletionBlocker",
+      args: ["/tmp/project", "main", "execute-task", "M001/S01/T01"],
+    },
+  ]);
+});
+
 test("runUnitPhase emits unit-start and unit-end with causedBy reference", async () => {
   const capture = createEventCapture();