refactor: extract workspace terminal sessions, improve sidebar drag-and-drop with nestable lists, and consolidate tab presentation logic

packages/app/src/utils/sidebar-gesture-arbitration.ts

@@ -1,14 +1,25 @@
-export type LongPressMoveDecision = "none" | "cancel_long_press" | "start_drag";
+export type LongPressMoveDecision =
+  | "none"
+  | "cancel_long_press"
+  | "vertical_scroll"
+  | "horizontal_swipe"
+  | "start_drag";
 
 export function decideLongPressMove(input: {
-  longPressArmed: boolean;
+  dragArmed: boolean;
   didStartDrag: boolean;
   startPoint: { x: number; y: number } | null;
   currentPoint: { x: number; y: number };
   cancelSlopPx?: number;
+  scrollSlopPx?: number;
+  swipeSlopPx?: number;
+  directionalDominanceRatio?: number;
   dragSlopPx?: number;
 }): LongPressMoveDecision {
   const cancelSlopPx = input.cancelSlopPx ?? 10;
+  const scrollSlopPx = input.scrollSlopPx ?? 6;
+  const swipeSlopPx = input.swipeSlopPx ?? 8;
+  const directionalDominanceRatio = input.directionalDominanceRatio ?? 1.5;
   const dragSlopPx = input.dragSlopPx ?? 8;
 
   if (!input.startPoint) {
@@ -20,9 +31,19 @@ export function decideLongPressMove(input: {
 
   const dx = input.currentPoint.x - input.startPoint.x;
   const dy = input.currentPoint.y - input.startPoint.y;
+  const absDx = Math.abs(dx);
+  const absDy = Math.abs(dy);
   const distance = Math.sqrt(dx * dx + dy * dy);
+  const clearlyVertical = absDy >= absDx * directionalDominanceRatio;
+  const clearlyHorizontal = absDx >= absDy * directionalDominanceRatio;
 
-  if (!input.longPressArmed) {
+  if (!input.dragArmed) {
+    if (clearlyVertical && absDy > scrollSlopPx) {
+      return "vertical_scroll";
+    }
+    if (clearlyHorizontal && absDx > swipeSlopPx) {
+      return "horizontal_swipe";
+    }
     return distance > cancelSlopPx ? "cancel_long_press" : "none";
   }
   return distance > dragSlopPx ? "start_drag" : "none";
@@ -34,4 +55,3 @@ export function shouldOpenContextMenuOnPressOut(input: {
 }): boolean {
   return input.longPressArmed && !input.didStartDrag;
 }
-