feat: Add conflict source branch detection and fix re-render cascade in BoardView

apps/server/src/routes/worktree/routes/list.ts

@@ -98,6 +98,7 @@ async function detectConflictState(worktreePath: string): Promise<{
   hasConflicts: boolean;
   conflictType?: 'merge' | 'rebase' | 'cherry-pick';
   conflictFiles?: string[];
+  conflictSourceBranch?: string;
 }> {
   try {
     // Find the canonical .git directory for this worktree (execGitCommand avoids /bin/sh in CI)
@@ -153,10 +154,84 @@ async function detectConflictState(worktreePath: string): Promise<{
       // Fall back to empty list if diff fails
     }
 
+    // Detect the source branch involved in the conflict
+    let conflictSourceBranch: string | undefined;
+    try {
+      if (conflictType === 'merge' && mergeHeadExists) {
+        // For merges, resolve MERGE_HEAD to a branch name
+        const mergeHead = (
+          await secureFs.readFile(path.join(gitDir, 'MERGE_HEAD'), 'utf-8')
+        ).trim();
+        try {
+          const branchName = await execGitCommand(
+            ['name-rev', '--name-only', '--refs=refs/heads/*', mergeHead],
+            worktreePath
+          );
+          const cleaned = branchName.trim().replace(/~\d+$/, '');
+          if (cleaned && cleaned !== 'undefined') {
+            conflictSourceBranch = cleaned;
+          }
+        } catch {
+          // Could not resolve to branch name
+        }
+      } else if (conflictType === 'rebase') {
+        // For rebases, read the onto branch from rebase-merge/head-name or rebase-apply/head-name
+        const headNamePath = rebaseMergeExists
+          ? path.join(gitDir, 'rebase-merge', 'onto-name')
+          : path.join(gitDir, 'rebase-apply', 'onto-name');
+        try {
+          const ontoName = (await secureFs.readFile(headNamePath, 'utf-8')).trim();
+          if (ontoName) {
+            conflictSourceBranch = ontoName.replace(/^refs\/heads\//, '');
+          }
+        } catch {
+          // onto-name may not exist; try to resolve the onto commit
+          try {
+            const ontoPath = rebaseMergeExists
+              ? path.join(gitDir, 'rebase-merge', 'onto')
+              : path.join(gitDir, 'rebase-apply', 'onto');
+            const ontoCommit = (await secureFs.readFile(ontoPath, 'utf-8')).trim();
+            if (ontoCommit) {
+              const branchName = await execGitCommand(
+                ['name-rev', '--name-only', '--refs=refs/heads/*', ontoCommit],
+                worktreePath
+              );
+              const cleaned = branchName.trim().replace(/~\d+$/, '');
+              if (cleaned && cleaned !== 'undefined') {
+                conflictSourceBranch = cleaned;
+              }
+            }
+          } catch {
+            // Could not resolve onto commit
+          }
+        }
+      } else if (conflictType === 'cherry-pick' && cherryPickHeadExists) {
+        // For cherry-picks, try to resolve CHERRY_PICK_HEAD to a branch name
+        const cherryPickHead = (
+          await secureFs.readFile(path.join(gitDir, 'CHERRY_PICK_HEAD'), 'utf-8')
+        ).trim();
+        try {
+          const branchName = await execGitCommand(
+            ['name-rev', '--name-only', '--refs=refs/heads/*', cherryPickHead],
+            worktreePath
+          );
+          const cleaned = branchName.trim().replace(/~\d+$/, '');
+          if (cleaned && cleaned !== 'undefined') {
+            conflictSourceBranch = cleaned;
+          }
+        } catch {
+          // Could not resolve to branch name
+        }
+      }
+    } catch {
+      // Ignore source branch detection errors
+    }
+
     return {
       hasConflicts: conflictFiles.length > 0,
       conflictType,
       conflictFiles,
+      conflictSourceBranch,
     };
   } catch {
     // If anything fails, assume no conflicts

apps/ui/src/components/views/board-view.tsx

@@ -715,15 +715,27 @@ export function BoardView({ initialFeatureId }: BoardViewProps) {
   const selectedWorktreeBranch =
     currentWorktreeBranch || worktrees.find((w) => w.isMain)?.branch || 'main';
 
-  // Aggregate running auto tasks across all worktrees for this project
+  // Aggregate running auto tasks across all worktrees for this project.
-  const autoModeByWorktree = useAppStore((state) => state.autoModeByWorktree);
+  // IMPORTANT: Use a derived selector with shallow equality instead of subscribing
-  const runningAutoTasksAllWorktrees = useMemo(() => {
+  // to the raw autoModeByWorktree object. The raw subscription caused the entire
-    if (!currentProject?.id) return [];
+  // BoardView to re-render on EVERY auto-mode state change (any worktree), which
-    const prefix = `${currentProject.id}::`;
+  // during worktree switches cascaded through DndContext/KanbanBoard and triggered
-    return Object.entries(autoModeByWorktree)
+  // React error #185 (maximum update depth exceeded), crashing the board view.
-      .filter(([key]) => key.startsWith(prefix))
+  const runningAutoTasksAllWorktrees = useAppStore(
-      .flatMap(([, state]) => state.runningTasks ?? []);
+    useShallow((state) => {
-  }, [autoModeByWorktree, currentProject?.id]);
+      if (!currentProject?.id) return [] as string[];
+      const prefix = `${currentProject.id}::`;
+      const tasks: string[] = [];
+      for (const [key, worktreeState] of Object.entries(state.autoModeByWorktree)) {
+        if (key.startsWith(prefix) && worktreeState.runningTasks) {
+          for (const task of worktreeState.runningTasks) {
+            tasks.push(task);
+          }
+        }
+      }
+      return tasks;
+    })
+  );
 
   // Get in-progress features for keyboard shortcuts (needed before actions hook)
   // Must be after runningAutoTasks is defined
@@ -1506,6 +1518,7 @@ export function BoardView({ initialFeatureId }: BoardViewProps) {
     runningAutoTasks: runningAutoTasksAllWorktrees,
     persistFeatureUpdate,
     handleStartImplementation,
+    stopFeature: autoMode.stopFeature,
   });
 
   // Handle dependency link creation

apps/ui/src/components/views/board-view/hooks/use-board-drag-drop.ts

@@ -1,9 +1,8 @@
-import { useState, useCallback } from 'react';
+import { useState, useCallback, useEffect } from 'react';
 import { createLogger } from '@automaker/utils/logger';
 import { DragStartEvent, DragEndEvent } from '@dnd-kit/core';
 import { Feature } from '@/store/app-store';
 import { useAppStore } from '@/store/app-store';
-import { useAutoMode } from '@/hooks/use-auto-mode';
 import { toast } from 'sonner';
 import { COLUMNS, ColumnId } from '../constants';
 
@@ -20,6 +19,7 @@ interface UseBoardDragDropProps {
   runningAutoTasks: string[];
   persistFeatureUpdate: (featureId: string, updates: Partial<Feature>) => Promise<void>;
   handleStartImplementation: (feature: Feature) => Promise<boolean>;
+  stopFeature: (featureId: string) => Promise<void>;
 }
 
 export function useBoardDragDrop({
@@ -28,6 +28,7 @@ export function useBoardDragDrop({
   runningAutoTasks,
   persistFeatureUpdate,
   handleStartImplementation,
+  stopFeature,
 }: UseBoardDragDropProps) {
   const [activeFeature, setActiveFeature] = useState<Feature | null>(null);
   const [pendingDependencyLink, setPendingDependencyLink] = useState<PendingDependencyLink | null>(
@@ -39,11 +40,22 @@ export function useBoardDragDrop({
   // and triggers React error #185 (maximum update depth exceeded).
   const moveFeature = useAppStore((s) => s.moveFeature);
   const updateFeature = useAppStore((s) => s.updateFeature);
-  const autoMode = useAutoMode();
 
   // Note: getOrCreateWorktreeForFeature removed - worktrees are now created server-side
   // at execution time based on feature.branchName
 
+  // Clear stale activeFeature when features list changes (e.g. during worktree switches).
+  // Without this, the DragOverlay in KanbanBoard can try to render a feature from
+  // a previous worktree, causing property access crashes.
+  useEffect(() => {
+    setActiveFeature((current) => {
+      if (!current) return null;
+      // If the active feature is no longer in the features list, clear it
+      const stillExists = features.some((f) => f.id === current.id);
+      return stillExists ? current : null;
+    });
+  }, [features]);
+
   const handleDragStart = useCallback(
     (event: DragStartEvent) => {
       const { active } = event;
@@ -244,7 +256,7 @@ export function useBoardDragDrop({
           // If the feature is currently running, stop it first
           if (isRunningTask) {
             try {
-              await autoMode.stopFeature(featureId);
+              await stopFeature(featureId);
               logger.info('Stopped running feature via drag to backlog:', featureId);
             } catch (error) {
               logger.error('Error stopping feature during drag to backlog:', error);
@@ -339,7 +351,7 @@ export function useBoardDragDrop({
       updateFeature,
       persistFeatureUpdate,
       handleStartImplementation,
-      autoMode,
+      stopFeature,
     ]
   );
 

apps/ui/src/components/views/board-view/worktree-panel/components/worktree-actions-dropdown.tsx

@@ -46,11 +46,19 @@ import {
   ArrowLeftRight,
   Check,
   Hash,
+  Sparkles,
 } from 'lucide-react';
 import { toast } from 'sonner';
 import { cn } from '@/lib/utils';
 import { Spinner } from '@/components/ui/spinner';
-import type { WorktreeInfo, DevServerInfo, PRInfo, GitRepoStatus, TestSessionInfo } from '../types';
+import type {
+  WorktreeInfo,
+  DevServerInfo,
+  PRInfo,
+  GitRepoStatus,
+  TestSessionInfo,
+  MergeConflictInfo,
+} from '../types';
 import { TooltipWrapper } from './tooltip-wrapper';
 import { useAvailableEditors, useEffectiveDefaultEditor } from '../hooks/use-available-editors';
 import {
@@ -137,6 +145,8 @@ interface WorktreeActionsDropdownProps {
   onAbortOperation?: (worktree: WorktreeInfo) => void;
   /** Continue an in-progress merge/rebase/cherry-pick after resolving conflicts */
   onContinueOperation?: (worktree: WorktreeInfo) => void;
+  /** Create a feature to resolve merge/rebase/cherry-pick conflicts with AI */
+  onCreateConflictResolutionFeature?: (conflictInfo: MergeConflictInfo) => void;
   hasInitScript: boolean;
   /** Terminal quick scripts configured for the project */
   terminalScripts?: TerminalScript[];
@@ -293,6 +303,7 @@ export function WorktreeActionsDropdown({
   onCherryPick,
   onAbortOperation,
   onContinueOperation,
+  onCreateConflictResolutionFeature,
   hasInitScript,
   terminalScripts,
   onRunTerminalScript,
@@ -467,6 +478,23 @@ export function WorktreeActionsDropdown({
                       : 'Operation'}
               </DropdownMenuItem>
             )}
+            {onCreateConflictResolutionFeature && (
+              <DropdownMenuItem
+                onClick={() =>
+                  onCreateConflictResolutionFeature({
+                    sourceBranch: worktree.branch,
+                    targetBranch: worktree.branch,
+                    targetWorktreePath: worktree.path,
+                    conflictFiles: worktree.conflictFiles,
+                    operationType: worktree.conflictType,
+                  })
+                }
+                className="text-xs text-purple-500 focus:text-purple-600"
+              >
+                <Sparkles className="w-3.5 h-3.5 mr-2" />
+                Resolve with AI
+              </DropdownMenuItem>
+            )}
             <DropdownMenuSeparator />
           </>
         )}

apps/ui/src/components/views/board-view/worktree-panel/components/worktree-dropdown.tsx

@@ -27,6 +27,7 @@ import type {
   PRInfo,
   GitRepoStatus,
   TestSessionInfo,
+  MergeConflictInfo,
 } from '../types';
 import { WorktreeDropdownItem } from './worktree-dropdown-item';
 import { BranchSwitchDropdown } from './branch-switch-dropdown';
@@ -129,6 +130,8 @@ export interface WorktreeDropdownProps {
   onAbortOperation?: (worktree: WorktreeInfo) => void;
   /** Continue an in-progress merge/rebase/cherry-pick after resolving conflicts */
   onContinueOperation?: (worktree: WorktreeInfo) => void;
+  /** Create a feature to resolve merge/rebase/cherry-pick conflicts with AI */
+  onCreateConflictResolutionFeature?: (conflictInfo: MergeConflictInfo) => void;
   /** Remotes cache: maps worktree path to list of remotes */
   remotesCache?: Record<string, Array<{ name: string; url: string }>>;
   /** Pull from a specific remote, bypassing the remote selection dialog */
@@ -241,6 +244,7 @@ export function WorktreeDropdown({
   onCherryPick,
   onAbortOperation,
   onContinueOperation,
+  onCreateConflictResolutionFeature,
   remotesCache,
   onPullWithRemote,
   onPushWithRemote,
@@ -607,6 +611,7 @@ export function WorktreeDropdown({
           onCherryPick={onCherryPick}
           onAbortOperation={onAbortOperation}
           onContinueOperation={onContinueOperation}
+          onCreateConflictResolutionFeature={onCreateConflictResolutionFeature}
           hasInitScript={hasInitScript}
           terminalScripts={terminalScripts}
           onRunTerminalScript={onRunTerminalScript}

apps/ui/src/components/views/board-view/worktree-panel/components/worktree-tab.tsx

@@ -12,6 +12,7 @@ import type {
   PRInfo,
   GitRepoStatus,
   TestSessionInfo,
+  MergeConflictInfo,
 } from '../types';
 import { BranchSwitchDropdown } from './branch-switch-dropdown';
 import { WorktreeActionsDropdown } from './worktree-actions-dropdown';
@@ -95,6 +96,8 @@ interface WorktreeTabProps {
   onAbortOperation?: (worktree: WorktreeInfo) => void;
   /** Continue an in-progress merge/rebase/cherry-pick after resolving conflicts */
   onContinueOperation?: (worktree: WorktreeInfo) => void;
+  /** Create a feature to resolve merge/rebase/cherry-pick conflicts with AI */
+  onCreateConflictResolutionFeature?: (conflictInfo: MergeConflictInfo) => void;
   hasInitScript: boolean;
   /** Whether a test command is configured in project settings */
   hasTestCommand?: boolean;
@@ -195,6 +198,7 @@ export function WorktreeTab({
   onCherryPick,
   onAbortOperation,
   onContinueOperation,
+  onCreateConflictResolutionFeature,
   hasInitScript,
   hasTestCommand = false,
   remotes,
@@ -579,6 +583,7 @@ export function WorktreeTab({
         onCherryPick={onCherryPick}
         onAbortOperation={onAbortOperation}
         onContinueOperation={onContinueOperation}
+        onCreateConflictResolutionFeature={onCreateConflictResolutionFeature}
         hasInitScript={hasInitScript}
         terminalScripts={terminalScripts}
         onRunTerminalScript={onRunTerminalScript}

apps/ui/src/components/views/board-view/worktree-panel/worktree-panel.tsx

@@ -1071,6 +1071,7 @@ export function WorktreePanel({
             onCherryPick={handleCherryPick}
             onAbortOperation={handleAbortOperation}
             onContinueOperation={handleContinueOperation}
+            onCreateConflictResolutionFeature={onCreateMergeConflictResolutionFeature}
             hasInitScript={hasInitScript}
             terminalScripts={terminalScripts}
             onRunTerminalScript={handleRunTerminalScript}
@@ -1310,6 +1311,7 @@ export function WorktreePanel({
           onCherryPick={handleCherryPick}
           onAbortOperation={handleAbortOperation}
           onContinueOperation={handleContinueOperation}
+          onCreateConflictResolutionFeature={onCreateMergeConflictResolutionFeature}
           terminalScripts={terminalScripts}
           onRunTerminalScript={handleRunTerminalScript}
           onEditScripts={handleEditScripts}
@@ -1391,6 +1393,7 @@ export function WorktreePanel({
             onCherryPick={handleCherryPick}
             onAbortOperation={handleAbortOperation}
             onContinueOperation={handleContinueOperation}
+            onCreateConflictResolutionFeature={onCreateMergeConflictResolutionFeature}
             hasInitScript={hasInitScript}
             hasTestCommand={hasTestCommand}
             terminalScripts={terminalScripts}
@@ -1478,6 +1481,7 @@ export function WorktreePanel({
               onCherryPick={handleCherryPick}
               onAbortOperation={handleAbortOperation}
               onContinueOperation={handleContinueOperation}
+              onCreateConflictResolutionFeature={onCreateMergeConflictResolutionFeature}
               hasInitScript={hasInitScript}
               hasTestCommand={hasTestCommand}
               terminalScripts={terminalScripts}

apps/ui/tests/features/feature-deep-link.spec.ts

@@ -28,7 +28,7 @@ test.describe('Feature Deep Link', () => {
   let projectPath: string;
   let projectName: string;
 
-  test.beforeEach(async (_fixtures, testInfo) => {
+  test.beforeEach(async ({}, testInfo) => {
     projectName = `test-project-${testInfo.workerIndex}-${Date.now()}`;
     projectPath = path.join(TEST_TEMP_DIR, projectName);
     fs.mkdirSync(projectPath, { recursive: true });