feat(core): implement git worktree checkpoint system

Add comprehensive worktree management system to enable task isolation and rollback capabilities. This allows users to revert agent changes if they don't satisfy requirements or break functionality.

Key components:
- New WorktreeManager service for branch and worktree operations
- GitDiffPanel component for visualizing changes
- Enhanced UI components with worktree integration
- Auto-mode service enhancements for worktree workflow

Modified files: worktree-manager.js, git-diff-panel.tsx, main.js, preload.js, feature-loader.js, agent-output-modal.tsx, board-view.tsx, kanban-card.tsx, electron.ts, app-store.ts, electron.d.ts

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4 <noreply@anthropic.com>

app/src/components/views/agent-output-modal.tsx

@@ -8,9 +8,10 @@ import {
   DialogHeader,
   DialogTitle,
 } from "@/components/ui/dialog";
-import { Loader2, List, FileText } from "lucide-react";
+import { Loader2, List, FileText, GitBranch } from "lucide-react";
 import { getElectronAPI } from "@/lib/electron";
 import { LogViewer } from "@/components/ui/log-viewer";
+import { GitDiffPanel } from "@/components/ui/git-diff-panel";
 import type { AutoModeEvent } from "@/types/electron";
 
 interface AgentOutputModalProps {
@@ -22,7 +23,7 @@ interface AgentOutputModalProps {
   onNumberKeyPress?: (key: string) => void;
 }
 
-type ViewMode = "parsed" | "raw";
+type ViewMode = "parsed" | "raw" | "changes";
 
 export function AgentOutputModal({
   open,
@@ -34,6 +35,7 @@ export function AgentOutputModal({
   const [output, setOutput] = useState<string>("");
   const [isLoading, setIsLoading] = useState(true);
   const [viewMode, setViewMode] = useState<ViewMode>("parsed");
+  const [projectPath, setProjectPath] = useState<string>("");
   const scrollRef = useRef<HTMLDivElement>(null);
   const autoScrollRef = useRef(true);
   const projectPathRef = useRef<string>("");
@@ -64,6 +66,7 @@ export function AgentOutputModal({
         }
 
         projectPathRef.current = currentProject.path;
+        setProjectPath(currentProject.path);
 
         // Ensure context directory exists
         const contextDir = `${currentProject.path}/.automaker/agents-context`;
@@ -257,7 +260,19 @@ export function AgentOutputModal({
                 data-testid="view-mode-parsed"
               >
                 <List className="w-3.5 h-3.5" />
-                Parsed
+                Logs
+              </button>
+              <button
+                onClick={() => setViewMode("changes")}
+                className={`flex items-center gap-1.5 px-3 py-1.5 rounded-md text-xs font-medium transition-all ${
+                  viewMode === "changes"
+                    ? "bg-primary/20 text-primary shadow-sm"
+                    : "text-muted-foreground hover:text-foreground hover:bg-accent"
+                }`}
+                data-testid="view-mode-changes"
+              >
+                <GitBranch className="w-3.5 h-3.5" />
+                Changes
               </button>
               <button
                 onClick={() => setViewMode("raw")}
@@ -281,34 +296,54 @@ export function AgentOutputModal({
           </DialogDescription>
         </DialogHeader>
 
-        <div
-          ref={scrollRef}
-          onScroll={handleScroll}
-          className="flex-1 overflow-y-auto bg-zinc-950 rounded-lg p-4 font-mono text-xs min-h-[400px] max-h-[60vh]"
-        >
-          {isLoading && !output ? (
-            <div className="flex items-center justify-center h-full text-muted-foreground">
-              <Loader2 className="w-6 h-6 animate-spin mr-2" />
-              Loading output...
+        {viewMode === "changes" ? (
+          <div className="flex-1 overflow-y-auto min-h-[400px] max-h-[60vh]">
+            {projectPath ? (
+              <GitDiffPanel
+                projectPath={projectPath}
+                featureId={featureId}
+                compact={false}
+                className="border-0 rounded-lg"
+              />
+            ) : (
+              <div className="flex items-center justify-center h-full text-muted-foreground">
+                <Loader2 className="w-6 h-6 animate-spin mr-2" />
+                Loading...
+              </div>
+            )}
+          </div>
+        ) : (
+          <>
+            <div
+              ref={scrollRef}
+              onScroll={handleScroll}
+              className="flex-1 overflow-y-auto bg-zinc-950 rounded-lg p-4 font-mono text-xs min-h-[400px] max-h-[60vh]"
+            >
+              {isLoading && !output ? (
+                <div className="flex items-center justify-center h-full text-muted-foreground">
+                  <Loader2 className="w-6 h-6 animate-spin mr-2" />
+                  Loading output...
+                </div>
+              ) : !output ? (
+                <div className="flex items-center justify-center h-full text-muted-foreground">
+                  No output yet. The agent will stream output here as it works.
+                </div>
+              ) : viewMode === "parsed" ? (
+                <LogViewer output={output} />
+              ) : (
+                <div className="whitespace-pre-wrap break-words text-zinc-300">
+                  {output}
+                </div>
+              )}
             </div>
-          ) : !output ? (
-            <div className="flex items-center justify-center h-full text-muted-foreground">
-              No output yet. The agent will stream output here as it works.
-            </div>
-          ) : viewMode === "parsed" ? (
-            <LogViewer output={output} />
-          ) : (
-            <div className="whitespace-pre-wrap break-words text-zinc-300">
-              {output}
-            </div>
-          )}
-        </div>
 
-        <div className="text-xs text-muted-foreground text-center flex-shrink-0">
-          {autoScrollRef.current
-            ? "Auto-scrolling enabled"
-            : "Scroll to bottom to enable auto-scroll"}
-        </div>
+            <div className="text-xs text-muted-foreground text-center flex-shrink-0">
+              {autoScrollRef.current
+                ? "Auto-scrolling enabled"
+                : "Scroll to bottom to enable auto-scroll"}
+            </div>
+          </>
+        )}
       </DialogContent>
     </Dialog>
   );

app/src/components/views/board-view.tsx

@@ -1090,6 +1090,106 @@ export function BoardView() {
     });
   };
 
+  // Revert feature changes by removing the worktree
+  const handleRevertFeature = async (feature: Feature) => {
+    if (!currentProject) return;
+
+    console.log("[Board] Reverting feature:", {
+      id: feature.id,
+      description: feature.description,
+      branchName: feature.branchName,
+    });
+
+    try {
+      const api = getElectronAPI();
+      if (!api?.worktree?.revertFeature) {
+        console.error("Worktree API not available");
+        toast.error("Revert not available", {
+          description: "This feature is not available in the current version.",
+        });
+        return;
+      }
+
+      const result = await api.worktree.revertFeature(
+        currentProject.path,
+        feature.id
+      );
+
+      if (result.success) {
+        console.log("[Board] Feature reverted successfully");
+        // Reload features to update the UI
+        await loadFeatures();
+        toast.success("Feature reverted", {
+          description: `All changes discarded. Moved back to backlog: ${feature.description.slice(
+            0,
+            50
+          )}${feature.description.length > 50 ? "..." : ""}`,
+        });
+      } else {
+        console.error("[Board] Failed to revert feature:", result.error);
+        toast.error("Failed to revert feature", {
+          description: result.error || "An error occurred",
+        });
+      }
+    } catch (error) {
+      console.error("[Board] Error reverting feature:", error);
+      toast.error("Failed to revert feature", {
+        description:
+          error instanceof Error ? error.message : "An error occurred",
+      });
+    }
+  };
+
+  // Merge feature worktree changes back to main branch
+  const handleMergeFeature = async (feature: Feature) => {
+    if (!currentProject) return;
+
+    console.log("[Board] Merging feature:", {
+      id: feature.id,
+      description: feature.description,
+      branchName: feature.branchName,
+    });
+
+    try {
+      const api = getElectronAPI();
+      if (!api?.worktree?.mergeFeature) {
+        console.error("Worktree API not available");
+        toast.error("Merge not available", {
+          description: "This feature is not available in the current version.",
+        });
+        return;
+      }
+
+      const result = await api.worktree.mergeFeature(
+        currentProject.path,
+        feature.id
+      );
+
+      if (result.success) {
+        console.log("[Board] Feature merged successfully");
+        // Reload features to update the UI
+        await loadFeatures();
+        toast.success("Feature merged", {
+          description: `Changes merged to main branch: ${feature.description.slice(
+            0,
+            50
+          )}${feature.description.length > 50 ? "..." : ""}`,
+        });
+      } else {
+        console.error("[Board] Failed to merge feature:", result.error);
+        toast.error("Failed to merge feature", {
+          description: result.error || "An error occurred",
+        });
+      }
+    } catch (error) {
+      console.error("[Board] Error merging feature:", error);
+      toast.error("Failed to merge feature", {
+        description:
+          error instanceof Error ? error.message : "An error occurred",
+      });
+    }
+  };
+
   const checkContextExists = async (featureId: string): Promise<boolean> => {
     if (!currentProject) return false;
 
@@ -1463,6 +1563,8 @@ export function BoardView() {
                             }
                             onFollowUp={() => handleOpenFollowUp(feature)}
                             onCommit={() => handleCommitFeature(feature)}
+                            onRevert={() => handleRevertFeature(feature)}
+                            onMerge={() => handleMergeFeature(feature)}
                             hasContext={featuresWithContext.has(feature.id)}
                             isCurrentAutoTask={runningAutoTasks.includes(
                               feature.id

app/src/components/views/kanban-card.tsx

@@ -49,6 +49,9 @@ import {
   FileText,
   MoreVertical,
   AlertCircle,
+  GitBranch,
+  Undo2,
+  GitMerge,
 } from "lucide-react";
 import { CountUpTimer } from "@/components/ui/count-up-timer";
 import { getElectronAPI } from "@/lib/electron";
@@ -72,6 +75,8 @@ interface KanbanCardProps {
   onMoveBackToInProgress?: () => void;
   onFollowUp?: () => void;
   onCommit?: () => void;
+  onRevert?: () => void;
+  onMerge?: () => void;
   hasContext?: boolean;
   isCurrentAutoTask?: boolean;
   shortcutKey?: string;
@@ -93,6 +98,8 @@ export function KanbanCard({
   onMoveBackToInProgress,
   onFollowUp,
   onCommit,
+  onRevert,
+  onMerge,
   hasContext,
   isCurrentAutoTask,
   shortcutKey,
@@ -101,9 +108,13 @@ export function KanbanCard({
 }: KanbanCardProps) {
   const [isDeleteDialogOpen, setIsDeleteDialogOpen] = useState(false);
   const [isSummaryDialogOpen, setIsSummaryDialogOpen] = useState(false);
+  const [isRevertDialogOpen, setIsRevertDialogOpen] = useState(false);
   const [agentInfo, setAgentInfo] = useState<AgentTaskInfo | null>(null);
   const { kanbanCardDetailLevel } = useAppStore();
 
+  // Check if feature has worktree
+  const hasWorktree = !!feature.branchName;
+
   // Helper functions to check what should be shown based on detail level
   const showSteps =
     kanbanCardDetailLevel === "standard" ||
@@ -246,11 +257,33 @@ export function KanbanCard({
           <span>Errored</span>
         </div>
       )}
+      {/* Branch badge - show when feature has a worktree */}
+      {hasWorktree && !isCurrentAutoTask && (
+        <div
+          className={cn(
+            "absolute px-1.5 py-0.5 text-[10px] font-medium rounded flex items-center gap-1 z-10",
+            "bg-purple-500/20 border border-purple-500/50 text-purple-400",
+            // Position below error badge if present, otherwise use normal position
+            feature.error || feature.skipTests
+              ? "top-8 left-2"
+              : shortcutKey
+                ? "top-2 left-10"
+                : "top-2 left-2"
+          )}
+          data-testid={`branch-badge-${feature.id}`}
+          title={`Branch: ${feature.branchName}`}
+        >
+          <GitBranch className="w-3 h-3" />
+          <span className="truncate max-w-[100px]">{feature.branchName?.replace("feature/", "")}</span>
+        </div>
+      )}
       <CardHeader
         className={cn(
           "p-3 pb-2 block", // Reset grid layout to block for custom kanban card layout
           // Add extra top padding when badges are present to prevent text overlap
-          (feature.skipTests || feature.error || shortcutKey) && "pt-10"
+          (feature.skipTests || feature.error || shortcutKey) && "pt-10",
+          // Add even more top padding when both badges and branch are shown
+          hasWorktree && (feature.skipTests || feature.error) && "pt-14"
         )}
       >
         {isCurrentAutoTask && (
@@ -615,6 +648,23 @@ export function KanbanCard({
           )}
           {!isCurrentAutoTask && feature.status === "waiting_approval" && (
             <>
+              {/* Revert button - only show when worktree exists */}
+              {hasWorktree && onRevert && (
+                <Button
+                  variant="ghost"
+                  size="sm"
+                  className="h-7 text-xs text-red-400 hover:text-red-300 hover:bg-red-500/20"
+                  onClick={(e) => {
+                    e.stopPropagation();
+                    setIsRevertDialogOpen(true);
+                  }}
+                  data-testid={`revert-${feature.id}`}
+                  title="Discard all changes and move back to backlog"
+                >
+                  <Undo2 className="w-3 h-3 mr-1" />
+                  Revert
+                </Button>
+              )}
               {/* Follow-up prompt button */}
               {onFollowUp && (
                 <Button
@@ -631,8 +681,25 @@ export function KanbanCard({
                   Follow-up
                 </Button>
               )}
-              {/* Commit and verify button */}
-              {onCommit && (
+              {/* Merge button - only show when worktree exists */}
+              {hasWorktree && onMerge && (
+                <Button
+                  variant="default"
+                  size="sm"
+                  className="flex-1 h-7 text-xs bg-purple-600 hover:bg-purple-700"
+                  onClick={(e) => {
+                    e.stopPropagation();
+                    onMerge();
+                  }}
+                  data-testid={`merge-${feature.id}`}
+                  title="Merge changes into main branch"
+                >
+                  <GitMerge className="w-3 h-3 mr-1" />
+                  Merge
+                </Button>
+              )}
+              {/* Commit and verify button - show when no worktree */}
+              {!hasWorktree && onCommit && (
                 <Button
                   variant="default"
                   size="sm"
@@ -736,6 +803,49 @@ export function KanbanCard({
           </DialogFooter>
         </DialogContent>
       </Dialog>
+
+      {/* Revert Confirmation Dialog */}
+      <Dialog open={isRevertDialogOpen} onOpenChange={setIsRevertDialogOpen}>
+        <DialogContent data-testid="revert-confirmation-dialog">
+          <DialogHeader>
+            <DialogTitle className="flex items-center gap-2 text-red-400">
+              <Undo2 className="w-5 h-5" />
+              Revert Changes
+            </DialogTitle>
+            <DialogDescription>
+              This will discard all changes made by the agent and move the feature back to the backlog.
+              {feature.branchName && (
+                <span className="block mt-2 font-medium">
+                  Branch <code className="bg-muted px-1 py-0.5 rounded">{feature.branchName}</code> will be deleted.
+                </span>
+              )}
+              <span className="block mt-2 text-red-400 font-medium">
+                This action cannot be undone.
+              </span>
+            </DialogDescription>
+          </DialogHeader>
+          <DialogFooter>
+            <Button
+              variant="ghost"
+              onClick={() => setIsRevertDialogOpen(false)}
+              data-testid="cancel-revert-button"
+            >
+              Cancel
+            </Button>
+            <Button
+              variant="destructive"
+              onClick={() => {
+                setIsRevertDialogOpen(false);
+                onRevert?.();
+              }}
+              data-testid="confirm-revert-button"
+            >
+              <Undo2 className="w-4 h-4 mr-2" />
+              Revert Changes
+            </Button>
+          </DialogFooter>
+        </DialogContent>
+      </Dialog>
     </Card>
   );
 }