feat(agent-ui): remove session + next active helpers (A6.195)

packages/agent-ui/README.md

@@ -310,6 +310,7 @@ consumption of shared panel shells:
 | A6.192 | Insert session after active tab |
 | A6.193 | Rename session title in list |
 | A6.194 | Apply session workspace target |
+| A6.195 | Remove session + next active id |
 
 ### A5 complete enough
 

packages/agent-ui/src/__tests__/removeSessionFromList.test.ts

@@ -0,0 +1,29 @@
+import { describe, expect, it } from "vitest";
+import {
+  nextActiveIdAfterDelete,
+  removeSessionFromList,
+} from "../lib/removeSessionFromList.js";
+
+describe("removeSessionFromList", () => {
+  it("filters id", () => {
+    expect(removeSessionFromList([{ id: "a" }, { id: "b" }], "a")).toEqual([
+      { id: "b" },
+    ]);
+  });
+});
+
+describe("nextActiveIdAfterDelete", () => {
+  it("picks next when active deleted", () => {
+    expect(
+      nextActiveIdAfterDelete([{ id: "a" }, { id: "b" }], "a", "a"),
+    ).toBe("b");
+  });
+  it("keeps active when other deleted", () => {
+    expect(
+      nextActiveIdAfterDelete([{ id: "a" }, { id: "b" }], "b", "a"),
+    ).toBe("a");
+  });
+  it("null when empty", () => {
+    expect(nextActiveIdAfterDelete([{ id: "a" }], "a", "a")).toBeNull();
+  });
+});

packages/agent-ui/src/index.ts

@@ -896,6 +896,10 @@ export { insertSessionAfterActive } from "./lib/insertSessionAfterActive.js";
 export { renameSessionInList } from "./lib/renameSessionInList.js";
 export type { SessionTitleMeta } from "./lib/renameSessionInList.js";
 export { applySessionWorkspaceTarget } from "./lib/sessionWorkspaceTarget.js";
+export {
+  removeSessionFromList,
+  nextActiveIdAfterDelete,
+} from "./lib/removeSessionFromList.js";
 export type {
   SessionWorkspaceTarget,
   SessionWorkspaceFields,

packages/agent-ui/src/lib/removeSessionFromList.ts

@@ -0,0 +1,26 @@
+/**
+ * Pure session-list delete helpers (A6.195).
+ */
+
+/** Drop a session id from the list. */
+export function removeSessionFromList<T extends { id: string }>(
+  sessions: readonly T[],
+  id: string,
+): T[] {
+  return sessions.filter((s) => s.id !== id);
+}
+
+/**
+ * After delete: remaining head if the deleted row was active; otherwise keep
+ * the current active id. Returns null when the list becomes empty.
+ */
+export function nextActiveIdAfterDelete(
+  sessions: readonly { id: string }[],
+  deletedId: string,
+  currentActiveId: string | null | undefined,
+): string | null {
+  const remaining = removeSessionFromList(sessions, deletedId);
+  if (remaining.length === 0) return null;
+  if (currentActiveId === deletedId) return remaining[0]!.id;
+  return currentActiveId ?? null;
+}

src/modules/ai/store/chatStore.ts

@@ -7,6 +7,8 @@ import {
   insertSessionAfterActive,
   renameSessionInList,
   applySessionWorkspaceTarget,
+  removeSessionFromList,
+  nextActiveIdAfterDelete,
 } from "@altai/agent-ui";
 import type { UIMessage } from "ai";
 import { native } from "../lib/native";
@@ -998,7 +1000,7 @@ export const useChatStore = create<StoreState>((set, get) => ({
       void requestStop(id).catch(() => undefined);
       return;
     }
-    const remaining = currentState.sessions.filter((s) => s.id !== id);
+    const remaining = removeSessionFromList(currentState.sessions, id);
     const pendingClarificationsBySession = {
       ...currentState.pendingClarificationsBySession,
     };
@@ -1042,7 +1044,11 @@ export const useChatStore = create<StoreState>((set, get) => ({
     const wasActive = currentState.activeSessionId === id;
     // remaining is non-empty here (the empty case returned above), so
     // remaining[0] is defined whenever we deleted the active session.
-    const nextActive = wasActive ? remaining[0].id : currentState.activeSessionId;
+    const nextActive = nextActiveIdAfterDelete(
+      currentState.sessions,
+      id,
+      currentState.activeSessionId,
+    );
     if (wasActive) {
       const pending = nextActive
         ? pendingClarificationsBySession[nextActive]