refactor: clarify branch name handling in feature dialogs

- Updated comments in AddFeatureDialog and EditFeatureDialog to better explain the logic for determining the final branch name based on the current worktree context.
- Adjusted logic to ensure that an empty string indicates "unassigned" for primary worktrees, while allowing for the use of the current branch when applicable.
- Simplified branch name handling in useBoardActions to reflect these changes.

apps/app/src/components/views/board-view/dialogs/add-feature-dialog.tsx

@@ -153,10 +153,11 @@ export function AddFeatureDialog({
       ? newFeature.thinkingLevel
       : "none";
 
-    // Use current branch if toggle is on (empty string = use current), otherwise use selected branch
-    // Important: Don't save the actual current branch name - empty string means "use current"
+    // Use current branch if toggle is on
+    // If currentBranch is provided (non-primary worktree), use it
+    // Otherwise (primary worktree), use empty string which means "unassigned" (show only on primary)
     const finalBranchName = useCurrentBranch
-      ? ""
+      ? (currentBranch || "")
       : newFeature.branchName || "";
 
     onAdd({

apps/app/src/components/views/board-view/dialogs/edit-feature-dialog.tsx

@@ -150,10 +150,11 @@ export function EditFeatureDialog({
       ? editingFeature.thinkingLevel ?? "none"
       : "none";
 
-    // Use current branch if toggle is on (empty string = use current), otherwise use selected branch
-    // Important: Don't save the actual current branch name - empty string means "use current"
+    // Use current branch if toggle is on
+    // If currentBranch is provided (non-primary worktree), use it
+    // Otherwise (primary worktree), use empty string which means "unassigned" (show only on primary)
     const finalBranchName = useCurrentBranch
-      ? ""
+      ? (currentBranch || "")
       : editingFeature.branchName || "";
 
     const updates = {

apps/app/src/components/views/board-view/hooks/use-board-actions.ts

@@ -102,7 +102,8 @@ export function useBoardActions({
     }) => {
       // Simplified: Only store branchName, no worktree creation on add
       // Worktrees are created at execution time (when feature starts)
-      // Empty string means user chose "use current branch" - don't save a branch name
+      // Empty string means "unassigned" (show only on primary worktree) - convert to undefined
+      // Non-empty string is the actual branch name (for non-primary worktrees)
       const finalBranchName = featureData.branchName || undefined;
 
       const newFeatureData = {