Preserve draft threads and speed up terminal startup

apps/web/src/components/ChatView.browser.tsx

@@ -1776,11 +1776,12 @@ describe("ChatView timeline estimator parity (full app)", () => {
 
       await newThreadButton.click();
 
-      await waitForURL(
+      const secondThreadPath = await waitForURL(
         mounted.router,
-        (path) => path === threadPath,
-        "New-thread should reuse the existing project draft thread.",
+        (path) => UUID_ROUTE_RE.test(path) && path !== threadPath,
+        "New-thread should create a fresh draft thread UUID.",
       );
+      const secondThreadId = secondThreadPath.slice(1) as ThreadId;
       expect(useComposerDraftStore.getState().draftsByThreadId[threadId]).toMatchObject({
         model: "gpt-5.4",
         modelOptions: {
@@ -1790,6 +1791,8 @@ describe("ChatView timeline estimator parity (full app)", () => {
           },
         },
       });
+      expect(useComposerDraftStore.getState().draftThreadsByThreadId[threadId]).toBeDefined();
+      expect(useComposerDraftStore.getState().draftThreadsByThreadId[secondThreadId]).toBeDefined();
     } finally {
       await mounted.cleanup();
     }

apps/web/src/components/ChatView.logic.ts

@@ -1,51 +1,21 @@
-import { type MessageId, ProjectId, type ThreadId } from "@okcode/contracts";
-import { type ChatMessage, type Thread } from "../types";
+import { type MessageId, ProjectId } from "@okcode/contracts";
+import { type ChatMessage } from "../types";
 import { randomUUID } from "~/lib/utils";
-import { type ComposerAttachment, type DraftThreadState } from "../composerDraftStore";
+import { type ComposerAttachment } from "../composerDraftStore";
 import { Schema } from "effect";
 import {
   filterTerminalContextsWithText,
   stripInlineTerminalContextPlaceholders,
   type TerminalContextDraft,
 } from "../lib/terminalContext";
 import { type PromptEnhancementId } from "../promptEnhancement";
-import { normalizeThreadTitle } from "../threadTitle";
+export { buildLocalDraftThread } from "../draftThreads";
 
 export const LAST_INVOKED_SCRIPT_BY_PROJECT_KEY = "okcode:last-invoked-script-by-project";
 const WORKTREE_BRANCH_PREFIX = "okcode";
 
 export const LastInvokedScriptByProjectSchema = Schema.Record(ProjectId, Schema.String);
 
-export function buildLocalDraftThread(
-  threadId: ThreadId,
-  draftThread: DraftThreadState,
-  fallbackModel: string,
-  error: string | null,
-): Thread {
-  return {
-    id: threadId,
-    codexThreadId: null,
-    projectId: draftThread.projectId,
-    title: normalizeThreadTitle(draftThread.title),
-    model: fallbackModel,
-    runtimeMode: draftThread.runtimeMode,
-    interactionMode: draftThread.interactionMode,
-    session: null,
-    messages: [],
-    error,
-    createdAt: draftThread.createdAt,
-    latestTurn: null,
-    lastVisitedAt: draftThread.createdAt,
-    branch: draftThread.branch,
-    worktreePath: draftThread.worktreePath,
-    worktreeBaseBranch: null,
-    ...(draftThread.githubRef ? { githubRef: draftThread.githubRef } : {}),
-    turnDiffSummaries: [],
-    activities: [],
-    proposedPlans: [],
-  };
-}
-
 export function revokeBlobPreviewUrl(previewUrl: string | undefined): void {
   if (!previewUrl || typeof URL === "undefined" || !previewUrl.startsWith("blob:")) {
     return;

apps/web/src/components/Sidebar.logic.test.ts

@@ -5,6 +5,7 @@ import {
   getVisibleThreadsForProject,
   getProjectSortTimestamp,
   hasUnseenCompletion,
+  mergeDraftThreadsIntoSidebarThreads,
   resolveProjectStatusIndicator,
   resolveProjectNameTone,
   resolveSidebarNewThreadEnvMode,
@@ -16,6 +17,7 @@ import {
   sortThreadsForSidebar,
 } from "./Sidebar.logic";
 import { ProjectId, ThreadId } from "@okcode/contracts";
+import type { DraftThreadState } from "../composerDraftStore";
 import {
   DEFAULT_INTERACTION_MODE,
   DEFAULT_RUNTIME_MODE,
@@ -99,6 +101,62 @@ describe("resolveSidebarNewThreadEnvMode", () => {
   });
 });
 
+describe("mergeDraftThreadsIntoSidebarThreads", () => {
+  it("includes preserved local drafts alongside server threads for the same project", () => {
+    const projectId = ProjectId.makeUnsafe("project-1");
+    const merged = mergeDraftThreadsIntoSidebarThreads({
+      serverThreads: [makeThread({ id: ThreadId.makeUnsafe("thread-server"), projectId })],
+      draftThreadsByThreadId: {
+        [ThreadId.makeUnsafe("thread-draft")]: {
+          projectId,
+          createdAt: "2026-03-09T11:00:00.000Z",
+          title: "Draft thread",
+          runtimeMode: DEFAULT_RUNTIME_MODE,
+          interactionMode: DEFAULT_INTERACTION_MODE,
+          branch: null,
+          worktreePath: null,
+          envMode: "local",
+        } satisfies DraftThreadState,
+      },
+      projectModelByProjectId: new Map([[projectId, "gpt-5.4"]]),
+    });
+
+    expect(merged.map((thread) => thread.id)).toEqual([
+      ThreadId.makeUnsafe("thread-server"),
+      ThreadId.makeUnsafe("thread-draft"),
+    ]);
+    expect(merged[1]).toMatchObject({
+      projectId,
+      title: "Draft thread",
+      model: "gpt-5.4",
+    });
+  });
+
+  it("skips draft entries once a server thread with the same id exists", () => {
+    const projectId = ProjectId.makeUnsafe("project-1");
+    const threadId = ThreadId.makeUnsafe("thread-shared");
+    const merged = mergeDraftThreadsIntoSidebarThreads({
+      serverThreads: [makeThread({ id: threadId, projectId })],
+      draftThreadsByThreadId: {
+        [threadId]: {
+          projectId,
+          createdAt: "2026-03-09T11:00:00.000Z",
+          title: "Promoted draft",
+          runtimeMode: DEFAULT_RUNTIME_MODE,
+          interactionMode: DEFAULT_INTERACTION_MODE,
+          branch: null,
+          worktreePath: null,
+          envMode: "local",
+        } satisfies DraftThreadState,
+      },
+      projectModelByProjectId: new Map([[projectId, "gpt-5.4"]]),
+    });
+
+    expect(merged).toHaveLength(1);
+    expect(merged[0]?.id).toBe(threadId);
+  });
+});
+
 describe("resolveThreadStatusPill", () => {
   const baseThread = {
     interactionMode: "plan" as const,

apps/web/src/components/Sidebar.logic.ts

@@ -1,4 +1,7 @@
+import { DEFAULT_MODEL_BY_PROVIDER } from "@okcode/contracts";
 import type { SidebarProjectSortOrder, SidebarThreadSortOrder } from "../appSettings";
+import type { DraftThreadState } from "../composerDraftStore";
+import { buildLocalDraftThread } from "../draftThreads";
 import type { Thread } from "../types";
 import { cn } from "../lib/utils";
 import {
@@ -283,6 +286,28 @@ export function groupThreadsByProjectId<TThread extends SidebarProjectThread>(
   return threadsByProjectId;
 }
 
+export function mergeDraftThreadsIntoSidebarThreads(input: {
+  serverThreads: readonly Thread[];
+  draftThreadsByThreadId: Readonly<Record<string, DraftThreadState>>;
+  projectModelByProjectId: ReadonlyMap<Thread["projectId"], string>;
+}): Thread[] {
+  const serverThreadIds = new Set(input.serverThreads.map((thread) => thread.id));
+  const mergedThreads = [...input.serverThreads];
+
+  for (const [threadId, draftThread] of Object.entries(input.draftThreadsByThreadId)) {
+    if (serverThreadIds.has(threadId as Thread["id"])) {
+      continue;
+    }
+    const fallbackModel =
+      input.projectModelByProjectId.get(draftThread.projectId) ?? DEFAULT_MODEL_BY_PROVIDER.codex;
+    mergedThreads.push(
+      buildLocalDraftThread(threadId as Thread["id"], draftThread, fallbackModel, null),
+    );
+  }
+
+  return mergedThreads;
+}
+
 function toSortableTimestamp(iso: string | undefined): number | null {
   if (!iso) return null;
   const ms = Date.parse(iso);