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.test.ts

@@ -9,7 +9,7 @@ describe("decideLongPressMove", () => {
   it("keeps long press pending for small movement before long-press arm", () => {
     expect(
       decideLongPressMove({
-        longPressArmed: false,
+        dragArmed: false,
         didStartDrag: false,
         startPoint: { x: 0, y: 0 },
         currentPoint: { x: 3, y: 2 },
@@ -20,18 +20,51 @@ describe("decideLongPressMove", () => {
   it("cancels long press when movement exceeds cancel slop before arm", () => {
     expect(
       decideLongPressMove({
-        longPressArmed: false,
+        dragArmed: false,
         didStartDrag: false,
         startPoint: { x: 0, y: 0 },
-        currentPoint: { x: 12, y: 0 },
+        currentPoint: { x: 8, y: 8 },
       })
     ).toBe("cancel_long_press");
   });
 
+  it("yields to vertical scroll before drag arm", () => {
+    expect(
+      decideLongPressMove({
+        dragArmed: false,
+        didStartDrag: false,
+        startPoint: { x: 0, y: 0 },
+        currentPoint: { x: 2, y: 7 },
+      })
+    ).toBe("vertical_scroll");
+  });
+
+  it("keeps diagonal motion neutral before drag arm", () => {
+    expect(
+      decideLongPressMove({
+        dragArmed: false,
+        didStartDrag: false,
+        startPoint: { x: 0, y: 0 },
+        currentPoint: { x: 5, y: 7 },
+      })
+    ).toBe("none");
+  });
+
+  it("yields to horizontal swipe before drag arm", () => {
+    expect(
+      decideLongPressMove({
+        dragArmed: false,
+        didStartDrag: false,
+        startPoint: { x: 0, y: 0 },
+        currentPoint: { x: -10, y: 2 },
+      })
+    ).toBe("horizontal_swipe");
+  });
+
   it("starts drag when movement exceeds drag slop after long-press arm", () => {
     expect(
       decideLongPressMove({
-        longPressArmed: true,
+        dragArmed: true,
         didStartDrag: false,
         startPoint: { x: 0, y: 0 },
         currentPoint: { x: 0, y: 9 },
@@ -42,7 +75,7 @@ describe("decideLongPressMove", () => {
   it("does nothing when drag already started", () => {
     expect(
       decideLongPressMove({
-        longPressArmed: true,
+        dragArmed: true,
         didStartDrag: true,
         startPoint: { x: 0, y: 0 },
         currentPoint: { x: 20, y: 20 },
@@ -75,4 +108,3 @@ describe("shouldOpenContextMenuOnPressOut", () => {
     ).toBe(false);
   });
 });
-

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;
 }
-

packages/app/src/utils/terminal-attach.test.ts

@@ -35,23 +35,29 @@ describe("terminal-attach", () => {
   it("reads and updates resume offsets monotonically", () => {
     const offsets = new Map<string, number>();
     const terminalId = "term-1";
+    const resumeOffsetStore = {
+      get: ({ terminalId }: { terminalId: string }) => offsets.get(terminalId),
+      set: ({ terminalId, offset }: { terminalId: string; offset: number }) => {
+        offsets.set(terminalId, offset);
+      },
+    };
 
     expect(
       getTerminalResumeOffset({
         terminalId,
-        resumeOffsetByTerminalId: offsets,
+        resumeOffsetStore,
       })
     ).toBeUndefined();
 
     updateTerminalResumeOffset({
       terminalId,
       offset: 8,
-      resumeOffsetByTerminalId: offsets,
+      resumeOffsetStore,
     });
     expect(
       getTerminalResumeOffset({
         terminalId,
-        resumeOffsetByTerminalId: offsets,
+        resumeOffsetStore,
       })
     ).toBe(8);
 
@@ -59,12 +65,12 @@ describe("terminal-attach", () => {
     updateTerminalResumeOffset({
       terminalId,
       offset: 3,
-      resumeOffsetByTerminalId: offsets,
+      resumeOffsetStore,
     });
     expect(
       getTerminalResumeOffset({
         terminalId,
-        resumeOffsetByTerminalId: offsets,
+        resumeOffsetStore,
       })
     ).toBe(8);
   });

packages/app/src/utils/terminal-attach.ts

@@ -8,11 +8,16 @@ const TERMINAL_ATTACH_RETRYABLE_ERROR_PATTERNS = [
   "stream ended",
 ] as const;
 
+export type TerminalResumeOffsetStore = {
+  get: (input: { terminalId: string }) => number | undefined;
+  set: (input: { terminalId: string; offset: number }) => void;
+};
+
 export function getTerminalResumeOffset(input: {
   terminalId: string;
-  resumeOffsetByTerminalId: Map<string, number>;
+  resumeOffsetStore: TerminalResumeOffsetStore;
 }): number | undefined {
-  const offset = input.resumeOffsetByTerminalId.get(input.terminalId);
+  const offset = input.resumeOffsetStore.get({ terminalId: input.terminalId });
   if (typeof offset !== "number" || !Number.isFinite(offset)) {
     return undefined;
   }
@@ -24,7 +29,7 @@ export function getTerminalResumeOffset(input: {
 export function updateTerminalResumeOffset(input: {
   terminalId: string;
   offset: number;
-  resumeOffsetByTerminalId: Map<string, number>;
+  resumeOffsetStore: TerminalResumeOffsetStore;
 }): void {
   if (!Number.isFinite(input.offset)) {
     return;
@@ -34,13 +39,16 @@ export function updateTerminalResumeOffset(input: {
   const previousOffset =
     getTerminalResumeOffset({
       terminalId: input.terminalId,
-      resumeOffsetByTerminalId: input.resumeOffsetByTerminalId,
+      resumeOffsetStore: input.resumeOffsetStore,
     }) ?? -1;
   if (normalizedOffset <= previousOffset) {
     return;
   }
 
-  input.resumeOffsetByTerminalId.set(input.terminalId, normalizedOffset);
+  input.resumeOffsetStore.set({
+    terminalId: input.terminalId,
+    offset: normalizedOffset,
+  });
 }
 
 export function getTerminalAttachRetryDelayMs(input: { attempt: number }): number {