fix: surface worktree setup errors instead of showing infinite spinner

staged/src/lib/features/branches/BranchCard.svelte

@@ -60,10 +60,12 @@
   interface Props {
     branch: Branch;
     deleting?: boolean;
+    worktreeError?: string;
     onDelete?: () => void;
+    onRetryWorktree?: () => void;
   }
 
-  let { branch, deleting = false, onDelete }: Props = $props();
+  let { branch, deleting = false, worktreeError, onDelete, onRetryWorktree }: Props = $props();
 
   // =========================================================================
   // PR button state
@@ -860,7 +862,10 @@
 <div
   class="branch-card"
   class:deleting
-  class:creating-worktree={branch.branchType === 'local' && !branch.worktreePath && !deleting}
+  class:creating-worktree={branch.branchType === 'local' &&
+    !branch.worktreePath &&
+    !worktreeError &&
+    !deleting}
 >
   {#if deleting}
     <div class="deleting-overlay">
@@ -875,12 +880,29 @@
         <span class="branch-separator">›</span>
         <span class="base-branch-name">{formatBaseBranch(branch.baseBranch)}</span>
       </div>
+      {#if worktreeError}
+        <div class="header-actions">
+          <button class="more-button" onclick={() => onDelete?.()} title="Delete branch">
+            <Trash2 size={16} />
+          </button>
+        </div>
+      {/if}
     </div>
     <div class="card-content">
-      <div class="loading">
-        <Spinner size={14} />
-        <span>Creating worktree…</span>
-      </div>
+      {#if worktreeError}
+        <div class="worktree-error">
+          <div class="worktree-error-message">
+            <AlertCircle size={14} />
+            <span>Failed to create worktree: {worktreeError}</span>
+          </div>
+          <button class="worktree-retry-btn" onclick={() => onRetryWorktree?.()}> Retry </button>
+        </div>
+      {:else}
+        <div class="loading">
+          <Spinner size={14} />
+          <span>Creating worktree…</span>
+        </div>
+      {/if}
     </div>
   {:else}
     <div class="card-header">
@@ -1598,6 +1620,48 @@
     font-size: var(--size-sm);
   }
 
+  /* Worktree error state */
+  .worktree-error {
+    display: flex;
+    align-items: center;
+    justify-content: space-between;
+    gap: 12px;
+  }
+
+  .worktree-error-message {
+    display: flex;
+    align-items: flex-start;
+    gap: 8px;
+    color: var(--ui-danger);
+    font-size: var(--size-sm);
+    line-height: 1.4;
+    min-width: 0;
+  }
+
+  .worktree-error-message :global(svg) {
+    flex-shrink: 0;
+    margin-top: 1px;
+  }
+
+  .worktree-retry-btn {
+    flex-shrink: 0;
+    padding: 5px 14px;
+    background: none;
+    border: 1px solid var(--border-muted);
+    border-radius: 6px;
+    color: var(--text-primary);
+    font-size: var(--size-xs);
+    font-weight: 500;
+    cursor: pointer;
+    transition: all 0.15s ease;
+  }
+
+  .worktree-retry-btn:hover {
+    border-color: var(--ui-accent);
+    color: var(--ui-accent);
+    background-color: var(--bg-hover);
+  }
+
   /* Footer */
   .card-footer {
     display: flex;

staged/src/lib/features/projects/ProjectHome.svelte

@@ -38,6 +38,9 @@
   let branchToDelete = $state<{ branch: Branch; project: Project } | null>(null);
   let deletingBranches = $state<Set<string>>(new Set());
 
+  // Worktree setup errors — maps branch ID → error message
+  let worktreeErrors = $state<Map<string, string>>(new Map());
+
   // Action detection state
   let detectingProjectIds = $state<Set<string>>(new Set());
 
@@ -168,32 +171,41 @@
     // For local branches without a worktree, set up the git worktree in the
     // background. The card will show "Creating worktree…" while this runs.
     if (branch.branchType === 'local' && !branch.worktreePath) {
-      const branchId = branch.id;
-      const projectId = branch.projectId;
-
-      commands
-        .setupWorktree(branchId)
-        .then((updated) => {
-          // Replace the branch record so the card picks up worktreePath
-          const branches = branchesByProject.get(projectId) || [];
-          branchesByProject = new Map(branchesByProject).set(
-            projectId,
-            branches.map((b) => (b.id === updated.id ? updated : b))
-          );
-
-          // Now that the worktree exists, run prerun actions
-          setTimeout(() => {
-            runPrerunActions(branchId, projectId).catch((e) => {
-              console.error('[ProjectHome] Failed to run prerun actions:', e);
-            });
-          }, 150);
-        })
-        .catch((e) => {
-          console.error('[ProjectHome] Failed to setup worktree:', e);
-        });
+      setupBranchWorktree(branch.id, branch.projectId);
     }
   }
 
+  /** Set up a git worktree for a branch, updating the UI on success or error. */
+  function setupBranchWorktree(branchId: string, projectId: string) {
+    // Clear any previous error for this branch
+    const nextErrors = new Map(worktreeErrors);
+    nextErrors.delete(branchId);
+    worktreeErrors = nextErrors;
+
+    commands
+      .setupWorktree(branchId)
+      .then((updated) => {
+        // Replace the branch record so the card picks up worktreePath
+        const branches = branchesByProject.get(projectId) || [];
+        branchesByProject = new Map(branchesByProject).set(
+          projectId,
+          branches.map((b) => (b.id === updated.id ? updated : b))
+        );
+
+        // Now that the worktree exists, run prerun actions
+        setTimeout(() => {
+          runPrerunActions(branchId, projectId).catch((e) => {
+            console.error('[ProjectHome] Failed to run prerun actions:', e);
+          });
+        }, 150);
+      })
+      .catch((e) => {
+        console.error('[ProjectHome] Failed to setup worktree:', e);
+        const errMsg = e instanceof Error ? e.message : typeof e === 'string' ? e : String(e);
+        worktreeErrors = new Map(worktreeErrors).set(branchId, errMsg);
+      });
+  }
+
   function handleDeleteBranchRequest(branchId: string, project: Project) {
     const branches = branchesByProject.get(project.id) || [];
     const branch = branches.find((b) => b.id === branchId);
@@ -323,10 +335,12 @@
             {project}
             branches={branchesByProject.get(project.id) || []}
             {deletingBranches}
+            {worktreeErrors}
             detecting={detectingProjectIds.has(project.id)}
             onDeleteProject={() => handleDeleteProjectRequest(project)}
             onDeleteBranch={(branchId) => handleDeleteBranchRequest(branchId, project)}
             onNewBranch={() => handleNewBranch(project)}
+            onRetryWorktree={(branchId) => setupBranchWorktree(branchId, project.id)}
           />
         {/each}
       </div>

staged/src/lib/features/projects/ProjectSection.svelte

@@ -17,20 +17,24 @@
     project: Project;
     branches: Branch[];
     deletingBranches?: Set<string>;
+    worktreeErrors?: Map<string, string>;
     detecting?: boolean;
     onDeleteProject?: () => void;
     onDeleteBranch?: (branchId: string) => void;
     onNewBranch?: () => void;
+    onRetryWorktree?: (branchId: string) => void;
   }
 
   let {
     project,
     branches,
     deletingBranches = new Set(),
+    worktreeErrors = new Map(),
     detecting = false,
     onDeleteProject,
     onDeleteBranch,
     onNewBranch,
+    onRetryWorktree,
   }: Props = $props();
 
   let showProjectSettings = $state(false);
@@ -75,7 +79,9 @@
         <BranchCard
           {branch}
           deleting={deletingBranches.has(branch.id)}
+          worktreeError={worktreeErrors.get(branch.id)}
           onDelete={() => onDeleteBranch?.(branch.id)}
+          onRetryWorktree={() => onRetryWorktree?.(branch.id)}
         />
       {/if}
     {/each}