Handle merge conflicts as orchestration events

src/ui/provider-executor.ts

@@ -333,7 +333,7 @@ function buildActorPrompt(input: ActorExecutionInput): string {
         },
         events: [
           {
-            type: "requirements_defined | tasks_planned | code_committed | task_ready_for_review | task_blocked | validation_passed | validation_failed | branch_merged",
+            type: "requirements_defined | tasks_planned | code_committed | task_ready_for_review | task_blocked | validation_passed | validation_failed | branch_merged | merge_conflict_detected | merge_conflict_resolved | merge_conflict_unresolved | merge_retry_started",
             payload: {
               summary: "optional",
               details: {},

src/ui/public/app.js

@@ -117,6 +117,10 @@ const MANIFEST_EVENT_TRIGGERS = [
   "validation_passed",
   "validation_failed",
   "branch_merged",
+  "merge_conflict_detected",
+  "merge_conflict_resolved",
+  "merge_conflict_unresolved",
+  "merge_retry_started",
 ];
 
 const RUN_MANIFEST_EDITOR_VALUE = "__editor__";

src/ui/run-service.ts

@@ -413,12 +413,22 @@ export class UiRunService {
       .map((task) => task.worktreePath)
       .filter((path): path is string => typeof path === "string" && path.trim().length > 0);
 
-    await runtime.worktreeManager.closeSession({
+    const outcome = await runtime.worktreeManager.closeSession({
       session,
       taskWorktreePaths,
       mergeBaseIntoProject: input.mergeToProject === true,
     });
 
+    if (outcome.kind === "fatal_error") {
+      throw new Error(`Session close failed: ${outcome.error}`);
+    }
+
+    if (outcome.kind === "conflict") {
+      return runtime.sessionStore.updateSession(session.sessionId, {
+        sessionStatus: "closed_with_conflicts",
+      });
+    }
+
     return runtime.sessionStore.updateSession(session.sessionId, {
       sessionStatus: "closed",
     });
@@ -448,7 +458,10 @@ export class UiRunService {
     if (input.sessionId?.trim() && !session) {
       throw new Error(`Session \"${sessionId}\" does not exist.`);
     }
-    if (session && session.sessionStatus === "closed") {
+    if (
+      session &&
+      (session.sessionStatus === "closed" || session.sessionStatus === "closed_with_conflicts")
+    ) {
       throw new Error(`Session \"${sessionId}\" is closed and cannot run new tasks.`);
     }
     const runId = randomUUID();