feat(chat): restore the run-location picker and isolate repository sessions by default

src/components/chat/hooks/useChatComposerState.ts

@@ -27,7 +27,15 @@ import { useSlashCommands } from './useSlashCommands';
 import { useWorkspaceTarget, type WorkspaceCandidate } from './useWorkspaceTarget';
 import { newQueuedDraftId, settleRetainedComposerSteer, useDurableComposerDraft } from './useDurableComposerDraft';
 
-interface UseChatComposerStateArgs { draftRepository?: ComposerDraftRepository; executionCwd?: string | null; selectedProject: Project | null; selectedSession: ProjectSession | null; currentSessionId: string | null; gjcModel: string; reasoningEffort?: string; isLoading: boolean; canAbortSession: boolean; tokenBudget: Record<string, unknown> | null; sendMessage: (message: unknown) => boolean | void; sendByCtrlEnter?: boolean; onSessionProcessing?: MarkSessionProcessing; onSessionEstablished?: (sessionId: string, context: SessionEstablishedContext) => void; onInputFocusChange?: (focused: boolean) => void; onCommandGateChange?: (gate: PendingCommandGate | null) => void; onShowSettings?: () => void; onLogin?: (providerId?: string) => void; scrollToBottom: () => void; addMessage: (msg: ChatMessage) => void; setIsUserScrolledUp: (isScrolledUp: boolean) => void; setPendingPermissionRequests: Dispatch<SetStateAction<PendingPermissionRequest[]>>; }
+interface UseChatComposerStateArgs { draftRepository?: ComposerDraftRepository; executionCwd?: string | null; selectedProject: Project | null; selectedSession: ProjectSession | null; currentSessionId: string | null; gjcModel: string; reasoningEffort?: string; isLoading: boolean; canAbortSession: boolean; tokenBudget: Record<string, unknown> | null; sendMessage: (message: unknown) => boolean | void; sendByCtrlEnter?: boolean; onSessionProcessing?: MarkSessionProcessing; onSessionEstablished?: (sessionId: string, context: SessionEstablishedContext) => void; onInputFocusChange?: (focused: boolean) => void; onCommandGateChange?: (gate: PendingCommandGate | null) => void; onShowSettings?: () => void; onLogin?: (providerId?: string) => void;
+  /**
+   * What the run-location picker shows before the user touches it.
+   *
+   * The caller owns this because the answer depends on whether the project is
+   * a git repository, which the composer never asks about. An untouched picker
+   * follows it; an explicit choice outranks it until the project changes.
+   */
+  defaultUseWorktree?: boolean; scrollToBottom: () => void; addMessage: (msg: ChatMessage) => void; setIsUserScrolledUp: (isScrolledUp: boolean) => void; setPendingPermissionRequests: Dispatch<SetStateAction<PendingPermissionRequest[]>>; }
 interface MentionableFile { name: string; path: string; }
 export type ModelCommandData = { current?: { provider?: string; providerLabel?: string; model?: string }; available?: Partial<Record<LLMProvider, string[]>>; availableModels?: string[]; availableOptions?: Array<{ value: string; label?: string; description?: string }>; defaultModel?: string; cache?: ProviderModelsCacheInfo; };
 export type CostCommandData = { tokenUsage?: { used?: number; total?: number }; tokenBreakdown?: { input?: number; output?: number }; provider?: string; model?: string; };
@@ -47,7 +55,7 @@ const resetBox = (setInput: (value: string) => void, value: MutableRefObject<str
 
 export function useChatComposerState(args: UseChatComposerStateArgs) {
   const { t } = useTranslation('chat');
-  const { executionCwd, selectedProject, selectedSession, currentSessionId, gjcModel, reasoningEffort = 'default', isLoading, canAbortSession, tokenBudget, sendMessage, sendByCtrlEnter, onSessionProcessing, onSessionEstablished, onInputFocusChange, onCommandGateChange, onShowSettings, onLogin, scrollToBottom, addMessage, setIsUserScrolledUp, setPendingPermissionRequests } = args;
+  const { executionCwd, selectedProject, selectedSession, currentSessionId, gjcModel, reasoningEffort = 'default', isLoading, canAbortSession, tokenBudget, sendMessage, sendByCtrlEnter, onSessionProcessing, onSessionEstablished, onInputFocusChange, onCommandGateChange, onShowSettings, onLogin, scrollToBottom, addMessage, setIsUserScrolledUp, setPendingPermissionRequests, defaultUseWorktree = false } = args;
   const projectId = selectedProject?.projectId;
   const conversation = selectedSession?.id || currentSessionId || null;
   const drafts = useDurableComposerDraft(projectId, conversation, args.draftRepository);
@@ -57,6 +65,12 @@ export function useChatComposerState(args: UseChatComposerStateArgs) {
   const [isTextareaExpanded, setExpanded] = useState(false);
   const [isInputFocused, setFocused] = useState(false);
   const [commandModalPayload, setModal] = useState<CommandModalPayload | null>(null);
+  // `null` means "not chosen", which is different from "chose Project": only
+  // the former follows `defaultUseWorktree` when it resolves, and the choice is
+  // dropped when the project changes so one project's answer is not carried
+  // into another that may not even be a repository.
+  const [worktreeChoice, setWorktreeChoice] = useState<boolean | null>(null);
+  const useWorktree = worktreeChoice ?? defaultUseWorktree;
   const [modelPickerTrigger, setModelPickerTrigger] = useState(0);
   const [pendingCommandGate, setGateState] = useState<PendingCommandGate | null>(null);
   const [queuePulse, setQueuePulse] = useState(0);
@@ -110,6 +124,11 @@ export function useChatComposerState(args: UseChatComposerStateArgs) {
       if (submissionOwner.current === owner) submissionOwner.current = null;
     };
   }, [conversation, projectId]);
+  // A run location is chosen per project. Carrying one project's answer into
+  // the next would silently pick a location for a repository the user never
+  // looked at - and for a project that is not a repository at all, the
+  // worktree route would simply fail.
+  useEffect(() => { setWorktreeChoice(null); }, [projectId]);
   useEffect(() => { inputRef.current = input; }, [input]);
   useEffect(() => { liveImages.current = attachedImages; }, [attachedImages]);
 
@@ -154,15 +173,18 @@ export function useChatComposerState(args: UseChatComposerStateArgs) {
     if (!isCurrent()) return null;
     const project = target ? await descend(target) : selectedProject;
     if (!isCurrent()) return null;
-    const response = await authenticatedFetch('/api/providers/sessions', { method: 'POST', body: JSON.stringify({ provider: 'gjc', projectPath: project?.fullPath || project?.path || '' }) });
+    // The worktree route allocates the session and its managed checkout in one
+    // transaction; the ordinary route binds the session to the project itself.
+    // Both return the same `sessionId`, so nothing downstream branches on this.
+    const response = await authenticatedFetch(useWorktree ? '/api/providers/worktree-sessions' : '/api/providers/sessions', { method: 'POST', body: JSON.stringify({ provider: 'gjc', projectPath: project?.fullPath || project?.path || '' }) });
     if (!response.ok) {
       const body = await response.json().catch(() => ({}));
       throw new Error(typeof body.error === 'string' ? body.error : body.error?.message ?? `Failed to create session (${response.status})`);
     }
     id = (await response.json())?.data?.sessionId || null;
     if (!id) throw new Error('no session id returned.');
     return { id, context: { provider: 'gjc', project: project!, summary } };
-  }, [currentSessionId, descend, resolveForSend, selectedProject, selectedSession]);
+  }, [currentSessionId, descend, resolveForSend, selectedProject, selectedSession, useWorktree]);
 
   const handleSubmit = useCallback(async (event: FormEvent<HTMLFormElement> | MouseEvent | TouchEvent | KeyboardEvent<HTMLTextAreaElement>, queued?: QueuedDraft) => {
     event.preventDefault(); const text = queued?.content ?? inputRef.current; if (!text.trim() || !selectedProject) return;
@@ -415,5 +437,5 @@ export function useChatComposerState(args: UseChatComposerStateArgs) {
     } finally { finishOperation(); }
   }, [sendMessage, setPendingPermissionRequests]);
   const handleInputFocusChange = useCallback((focused: boolean) => { setFocused(focused); onInputFocusChange?.(focused); }, [onInputFocusChange]);
-  return { composerFrozen, draftPersistence, draftReady, retryDraftPersistence, input, setInput, textareaRef, inputHighlightRef, isTextareaExpanded, slashCommandsCount, skillCommands: slashCommands.filter((command) => command.type === 'skill'), filteredCommands, frequentCommands, commandQuery, showCommandMenu, selectedCommandIndex, resetCommandMenuState, handleCommandSelect, handleToggleCommandMenu, showFileDropdown, filteredFiles: filteredFiles as MentionableFile[], selectedFileIndex, renderInputWithMentions, selectFile, attachedImages, setAttachedImages, attachmentNotice, dismissAttachmentNotice: () => setAttachmentNotice(null), getRootProps, getInputProps, isDragActive, openImagePicker: open, handleSubmit, handleSteer, modelPickerTrigger, queuedDrafts, editQueuedDraft, deleteQueuedDraft, moveQueuedDraft, resolveSteerResult, pendingCommandGate, confirmCommandGate, cancelCommandGate, handleVoiceTranscript, insertAtEnd, handleInputChange, handleKeyDown, handlePaste, handleTextareaClick: (event: MouseEvent<HTMLTextAreaElement>) => setCursorPosition(event.currentTarget.selectionStart), handleTextareaInput, syncInputOverlayScroll, handleClearInput, handleAbortSession, handlePermissionDecision, handleInputFocusChange, isInputFocused, commandModalPayload, closeCommandModal: () => setModal(null), showCostModal, isWorkspace: workspaceTarget.isWorkspace, workspaceCandidates: workspaceTarget.candidates, workspaceTargetValue: workspaceTarget.target, pickWorkspaceTarget: workspaceTarget.pickTarget };
+  return { useWorktree, setUseWorktree: setWorktreeChoice, composerFrozen, draftPersistence, draftReady, retryDraftPersistence, input, setInput, textareaRef, inputHighlightRef, isTextareaExpanded, slashCommandsCount, skillCommands: slashCommands.filter((command) => command.type === 'skill'), filteredCommands, frequentCommands, commandQuery, showCommandMenu, selectedCommandIndex, resetCommandMenuState, handleCommandSelect, handleToggleCommandMenu, showFileDropdown, filteredFiles: filteredFiles as MentionableFile[], selectedFileIndex, renderInputWithMentions, selectFile, attachedImages, setAttachedImages, attachmentNotice, dismissAttachmentNotice: () => setAttachmentNotice(null), getRootProps, getInputProps, isDragActive, openImagePicker: open, handleSubmit, handleSteer, modelPickerTrigger, queuedDrafts, editQueuedDraft, deleteQueuedDraft, moveQueuedDraft, resolveSteerResult, pendingCommandGate, confirmCommandGate, cancelCommandGate, handleVoiceTranscript, insertAtEnd, handleInputChange, handleKeyDown, handlePaste, handleTextareaClick: (event: MouseEvent<HTMLTextAreaElement>) => setCursorPosition(event.currentTarget.selectionStart), handleTextareaInput, syncInputOverlayScroll, handleClearInput, handleAbortSession, handlePermissionDecision, handleInputFocusChange, isInputFocused, commandModalPayload, closeCommandModal: () => setModal(null), showCostModal, isWorkspace: workspaceTarget.isWorkspace, workspaceCandidates: workspaceTarget.candidates, workspaceTargetValue: workspaceTarget.target, pickWorkspaceTarget: workspaceTarget.pickTarget };
 }

src/components/chat/view/ChatComposer.tsx

@@ -88,6 +88,8 @@ interface ChatComposerProps {
   isDragActive: boolean;
   /** Model pinned to this session, if any; outranks the last-run model. */
   sessionPinnedModel?: string | null;
+  /** The run-location control, rendered first among the composer tools. */
+  sessionLocationControl?: ReactNode;
   queuedDrafts: QueuedDraft[];
   onEditQueuedDraft: (index: number) => void;
   onDeleteQueuedDraft: (index: number) => void;
@@ -166,6 +168,7 @@ export default function ChatComposer({
   onSteer,
   isDragActive,
   sessionPinnedModel,
+  sessionLocationControl,
   queuedDrafts,
   onEditQueuedDraft,
   onDeleteQueuedDraft,
@@ -484,6 +487,8 @@ export default function ChatComposer({
             can wrap separately when a split pane leaves too little room.
           */}
           <PromptInputTools className="min-w-32 flex-1 basis-0 flex-wrap gap-y-1">
+            {sessionLocationControl}
+
             <PromptInputButton
               tooltip={{ content: t('input.attachImages') }}
               onClick={openImagePicker}

src/components/chat/view/ChatInterface.tsx

@@ -11,6 +11,7 @@ import { useLegacySkipPermissionsMigration, useProjectPermissions } from '../../
 import type { ProjectSession } from '../../../types/app';
 import { useChatComposerState } from '../hooks/useChatComposerState';
 import { useSessionLocation } from '../hooks/useSessionLocation';
+import { useProjectGitSummary } from '../../workspace/hooks/useProjectGitSummary';
 import { useChatProviderState } from '../hooks/useChatProviderState';
 import { useChatRealtimeHandlers } from '../hooks/useChatRealtimeHandlers';
 import { useChatSessionState } from '../hooks/useChatSessionState';
@@ -21,6 +22,7 @@ import { deriveLiveActivity } from '../utils/toolActivity';
 import OAuthLoginDialog from '../OAuthLoginDialog';
 import { useGoalControls } from '../hooks/useGoalControls';
 
+import SessionWorktreePicker from './SessionWorktreePicker';
 import GoalControls from './GoalControls';
 import ChatComposer from './ChatComposer';
 import ChatMessagesPane from './ChatMessagesPane';
@@ -87,7 +89,15 @@ function ChatInterface({
   });
 
   const { setCurrentSessionId } = session;
-  const sessionLocation = useSessionLocation(selectedSession?.id ?? session.currentSessionId);
+  const locationSessionId = selectedSession?.id ?? session.currentSessionId;
+  const sessionLocation = useSessionLocation(locationSessionId);
+  // A managed worktree is a git worktree, so it exists only for a repository.
+  // The summary is the same query the Environment rail already runs, and it is
+  // the only thing here that knows the answer: until it does, or when it says
+  // no, the picker stays on the project so the worktree route is never called
+  // where it would simply fail.
+  const projectGit = useProjectGitSummary(selectedProject?.projectId, Boolean(selectedProject?.projectId), locationSessionId ?? undefined, selectedProject?.fullPath);
+  const projectIsRepository = projectGit.state.kind === 'ready';
   const establishSession = useCallback<NonNullable<ChatInterfaceProps['onSessionEstablished']>>((id, context) => {
     setCurrentSessionId(id);
     onSessionEstablished?.(id, context);
@@ -96,6 +106,10 @@ function ChatInterface({
 
   const composer = useChatComposerState({
     executionCwd: sessionLocation.data?.cwd,
+    // An unattended run commits, pushes and switches branches on whatever
+    // checkout it was given, so a repository session starts isolated and the
+    // user opts back into the shared checkout rather than out of it.
+    defaultUseWorktree: projectIsRepository,
     selectedProject,
     selectedSession,
     currentSessionId: session.currentSessionId,
@@ -247,6 +261,9 @@ function ChatInterface({
       onSteer={composer.handleSteer}
       isDragActive={composer.isDragActive}
       sessionPinnedModel={sessionPinnedModel}
+      sessionLocationControl={projectIsRepository || locationSessionId
+        ? <SessionWorktreePicker value={composer.useWorktree} onChange={composer.setUseWorktree} sessionId={locationSessionId} location={sessionLocation.data} disabled={session.isProcessing} />
+        : null}
       queuedDrafts={composer.queuedDrafts}
       onEditQueuedDraft={composer.editQueuedDraft}
       onDeleteQueuedDraft={composer.deleteQueuedDraft}