feat(FN-2944): merge fusion/fn-2944

- test(FN-2944): cover already checked out worktree conflict recovery
- fix(FN-2944): recognize git already checked out worktree conflict
- fix(engine): auto-recover from squash-merge orphan rebase failures

Fusion-Task-Id: FN-2944

packages/dashboard/app/components/DirectoryPicker.tsx

@@ -1,6 +1,7 @@
 import { useState, useCallback, useEffect } from "react";
 import { Folder, FolderOpen, ChevronRight, ChevronUp, Loader2, Eye, EyeOff, AlertCircle } from "lucide-react";
 import { browseDirectory, type BrowseDirectoryResult } from "../api";
+import { getPathBreadcrumbs } from "../utils/pathDisplay";
 import "./DirectoryPicker.css";
 
 export interface DirectoryPickerProps {
@@ -99,9 +100,7 @@ export function DirectoryPicker({ value, onChange, placeholder, onInputKeyDown,
     }
   }, [browser.showHidden]);
 
-  const breadcrumbs = browser.currentPath
-    ? browser.currentPath.split("/").filter(Boolean)
-    : [];
+  const breadcrumbs = browser.currentPath ? getPathBreadcrumbs(browser.currentPath) : [];
 
   return (
     <div className="directory-picker">
@@ -129,26 +128,17 @@ export function DirectoryPicker({ value, onChange, placeholder, onInputKeyDown,
         <div className="directory-picker-browser" role="tree" aria-label="Directory browser">
           {/* Breadcrumbs */}
           <div className="directory-picker-breadcrumbs">
-            <button
-              type="button"
-              className="directory-picker-breadcrumb"
-              onClick={() => handleNavigate("/")}
-              title="Root"
-            >
-              /
-            </button>
-            {breadcrumbs.map((segment, i) => {
-              const segPath = "/" + breadcrumbs.slice(0, i + 1).join("/");
+            {breadcrumbs.map((breadcrumb, index) => {
               return (
-                <span key={segPath} className="directory-picker-breadcrumb-item">
-                  <ChevronRight size={12} className="directory-picker-breadcrumb-sep" />
+                <span key={breadcrumb.path} className="directory-picker-breadcrumb-item">
+                  {index > 0 && <ChevronRight size={12} className="directory-picker-breadcrumb-sep" />}
                   <button
                     type="button"
                     className="directory-picker-breadcrumb"
-                    onClick={() => handleNavigate(segPath)}
-                    title={segPath}
+                    onClick={() => handleNavigate(breadcrumb.path)}
+                    title={breadcrumb.path}
                   >
-                    {segment}
+                    {breadcrumb.label}
                   </button>
                 </span>
               );

packages/dashboard/app/components/FileBrowser.tsx

@@ -5,6 +5,7 @@ import type { FileNode } from "../api";
 import { copyFile, moveFile, deleteFile, renameFile, downloadFileUrl, downloadZipUrl } from "../api";
 import { appendTokenQuery } from "../auth";
 import { getErrorMessage } from "@fusion/core";
+import { getParentDisplayPath, joinDisplayPath, normalizeDisplayPath } from "../utils/pathDisplay";
 
 interface FileBrowserProps {
   entries: FileNode[];
@@ -37,7 +38,7 @@ function formatTime(mtime?: string): string {
 
 /** Build the full relative path for a file/directory entry */
 function entryPath(currentPath: string, name: string): string {
-  return currentPath === "." ? name : `${currentPath}/${name}`;
+  return joinDisplayPath(currentPath, name);
 }
 
 // ── Context Menu State ──────────────────────────────────────────────────
@@ -550,16 +551,14 @@ export function FileBrowser({
           <button
             className="file-browser-up"
             onClick={() => {
-              const parts = currentPath.split("/").filter(Boolean);
-              parts.pop();
-              onNavigate(parts.length === 0 ? "." : parts.join("/"));
+              onNavigate(getParentDisplayPath(currentPath));
             }}
           >
             <ChevronRight size={16} style={{ transform: "rotate(-90deg)" }} />
             Up one level
           </button>
         )}
-        <span className="file-browser-path">{currentPath === "." ? "Root" : currentPath}</span>
+        <span className="file-browser-path">{currentPath === "." ? "Root" : normalizeDisplayPath(currentPath)}</span>
       </div>
 
       <div className="file-browser-list">

packages/dashboard/app/components/FileMentionPopup.tsx

@@ -1,5 +1,6 @@
 import { File } from "lucide-react";
 import type { FileSearchItem } from "../hooks/useFileMention";
+import { getDisplayDirname } from "../utils/pathDisplay";
 import "./FileMentionPopup.css";
 
 import type { ReactNode } from "react";
@@ -54,7 +55,7 @@ export function FileMentionPopup({
       {!loading && files.length > 0 && (
         <ul className="file-mention-popup-list" role="listbox">
           {files.map((file, index) => {
-            const dirPath = file.path.includes("/") ? file.path.slice(0, file.path.lastIndexOf("/") + 1) : "";
+            const dirPath = getDisplayDirname(file.path);
             const highlightName = file.name;
 
             return (
@@ -85,4 +86,4 @@ export function FileMentionPopup({
       )}
     </div>
   );
-}
+}

packages/dashboard/app/components/GitManagerModal.tsx

@@ -5,6 +5,7 @@ import { getErrorMessage } from "@fusion/core";
 import type { ToastType } from "../hooks/useToast";
 import { useConfirm } from "../hooks/useConfirm";
 import { truncateMiddle } from "../utils/truncatePath";
+import { getPathBasename } from "../utils/pathDisplay";
 import { useModalResizePersist } from "../hooks/useModalResizePersist";
 import { useOverlayDismiss } from "../hooks/useOverlayDismiss";
 import type {
@@ -1624,7 +1625,7 @@ function WorktreesPanel({ worktrees }: { worktrees: GitWorktree[] }) {
                 {worktree.isMain && <span className="gm-badge main">main</span>}
                 {worktree.isBare && <span className="gm-badge bare">bare</span>}
                 <span className="gm-worktree-path" title={worktree.path}>
-                  {worktree.path.split("/").pop() || worktree.path}
+                  {getPathBasename(worktree.path) || worktree.path}
                 </span>
               </div>
               <div className="gm-worktree-detail">

packages/dashboard/app/components/Header.tsx

@@ -10,6 +10,7 @@ import { NodeStatusIndicator } from "./NodeStatusIndicator";
 import { NodeHealthDot } from "./NodeHealthDot";
 import { PluginSlot } from "./PluginSlot";
 import { useViewportMode, type ViewportMode } from "../hooks/useViewportMode";
+import { getTrailingPath } from "../utils/pathDisplay";
 
 export { useViewportMode };
 
@@ -114,7 +115,7 @@ function ProjectSelector({
                     <div className="project-selector-info">
                       <span className="project-selector-name">{project.name}</span>
                       <span className="project-selector-path">
-                        {project.path.split("/").slice(-2).join("/")}
+                        {getTrailingPath(project.path, 2)}
                       </span>
                     </div>
                     {isCurrent && <Check size={14} className="project-selector-check" />}
@@ -874,7 +875,7 @@ export function Header({
                       <div className="mobile-project-switch-info">
                         <span className="mobile-project-switch-name">{project.name}</span>
                         <span className="mobile-project-switch-path">
-                          {project.path.split("/").slice(-2).join("/")}
+                          {getTrailingPath(project.path, 2)}
                         </span>
                       </div>
                       {isCurrent && <Check size={14} className="mobile-project-switch-check" />}

packages/dashboard/app/components/ProjectSelector.tsx

@@ -15,6 +15,7 @@ import {
 } from "lucide-react";
 import type { ProjectInfo } from "../api";
 import type { ProjectStatus } from "@fusion/core";
+import { getTrailingPath } from "../utils/pathDisplay";
 
 export interface ProjectSelectorProps {
   projects: ProjectInfo[];
@@ -354,7 +355,7 @@ export function ProjectSelector({
                         {project.name}
                       </span>
                       <span className="project-selector__item-path">
-                        {project.path.split("/").slice(-2).join("/")}
+                        {getTrailingPath(project.path, 2)}
                       </span>
                     </div>
                     {currentProject?.id === project.id && (

packages/dashboard/app/components/TerminalModal.tsx

@@ -13,6 +13,7 @@ import {
 import { useTerminal } from "../hooks/useTerminal";
 import { useTerminalSessions } from "../hooks/useTerminalSessions";
 import { useModalResizePersist } from "../hooks/useModalResizePersist";
+import { getPathBasename } from "../utils/pathDisplay";
 import "@xterm/xterm/css/xterm.css";
 
 import type { Terminal as XTerm, ITerminalAddon } from "@xterm/xterm";
@@ -750,7 +751,7 @@ export function TerminalModal({ isOpen, onClose, initialCommand, projectId }: Te
 
     const unsubConnect = onConnect((info) => {
       // Update tab title with shell name
-      updateTabTitle(activeTab.id, info.shell.split("/").pop() || info.shell);
+      updateTabTitle(activeTab.id, getPathBasename(info.shell) || info.shell);
     });
 
     const unsubExit = onExit((code) => {

packages/dashboard/app/utils/pathDisplay.ts

@@ -0,0 +1,92 @@
+export interface PathBreadcrumb {
+  label: string;
+  path: string;
+}
+
+export function normalizeDisplayPath(path: string): string {
+  return path.replace(/\\/g, "/");
+}
+
+function trimTrailingSeparators(path: string): string {
+  return path.replace(/[\\/]+$/g, "");
+}
+
+export function splitPathSegments(path: string): string[] {
+  const normalized = normalizeDisplayPath(trimTrailingSeparators(path));
+  if (!normalized) return [];
+  return normalized.split("/").filter(Boolean);
+}
+
+export function getPathBasename(path: string): string {
+  const normalized = normalizeDisplayPath(trimTrailingSeparators(path));
+  if (!normalized) return path;
+  const segments = normalized.split("/").filter(Boolean);
+  return segments[segments.length - 1] || normalized;
+}
+
+export function getTrailingPath(path: string, count: number): string {
+  const segments = splitPathSegments(path);
+  if (segments.length === 0) {
+    return normalizeDisplayPath(path);
+  }
+  return segments.slice(-count).join("/");
+}
+
+export function getDisplayDirname(path: string): string {
+  const normalized = normalizeDisplayPath(trimTrailingSeparators(path));
+  const lastSeparator = normalized.lastIndexOf("/");
+  if (lastSeparator < 0) return "";
+  return normalized.slice(0, lastSeparator + 1);
+}
+
+export function joinDisplayPath(basePath: string, name: string): string {
+  if (!basePath || basePath === ".") {
+    return name;
+  }
+  const segments = splitPathSegments(basePath);
+  return [...segments, name].join("/");
+}
+
+export function getParentDisplayPath(path: string): string {
+  const segments = splitPathSegments(path);
+  if (segments.length === 0) {
+    return ".";
+  }
+  segments.pop();
+  return segments.length === 0 ? "." : segments.join("/");
+}
+
+export function getPathBreadcrumbs(path: string): PathBreadcrumb[] {
+  const normalized = normalizeDisplayPath(path);
+  const winMatch = normalized.match(/^([A-Za-z]:)(?:\/(.*))?$/);
+  if (winMatch) {
+    const root = `${winMatch[1]}/`;
+    const segments = (winMatch[2] ?? "").split("/").filter(Boolean);
+    const breadcrumbs: PathBreadcrumb[] = [{ label: winMatch[1], path: root }];
+    for (let i = 0; i < segments.length; i += 1) {
+      breadcrumbs.push({
+        label: segments[i]!,
+        path: `${root}${segments.slice(0, i + 1).join("/")}`,
+      });
+    }
+    return breadcrumbs;
+  }
+
+  if (normalized.startsWith("/")) {
+    const segments = normalized.split("/").filter(Boolean);
+    const breadcrumbs: PathBreadcrumb[] = [{ label: "/", path: "/" }];
+    for (let i = 0; i < segments.length; i += 1) {
+      breadcrumbs.push({
+        label: segments[i]!,
+        path: `/${segments.slice(0, i + 1).join("/")}`,
+      });
+    }
+    return breadcrumbs;
+  }
+
+  const segments = normalized.split("/").filter(Boolean);
+  return segments.map((segment, index) => ({
+    label: segment,
+    path: segments.slice(0, index + 1).join("/"),
+  }));
+}

packages/dashboard/app/utils/worktreeGrouping.ts

@@ -1,4 +1,5 @@
 import type { Task } from "@fusion/core";
+import { getPathBasename } from "./pathDisplay";
 
 export interface WorktreeGroupData {
   label: string;
@@ -11,9 +12,7 @@ export interface WorktreeGroupData {
  * e.g. ".worktrees/FN-001" → "FN-001", "/path/to/fn/fn-001" → "fn-001"
  */
 export function getWorktreeLabel(worktreePath: string): string {
-  // Take the last segment of the path
-  const segments = worktreePath.replace(/\/+$/, "").split("/");
-  return segments[segments.length - 1] || worktreePath;
+  return getPathBasename(worktreePath) || worktreePath;
 }
 
 /**