fix(layout): drop cross-env width propagation — defaults stay unchanged

User feedback: the initial sidebar width on a brand-new task should be
the same as it was before this PR (350px on typical viewports). The
plan's "propagate preferred widths across envs" feature changed that
in practice: after the first resize, every new task opened at the
resized width instead of the legacy default.

- Remove `getPinnedDefaults` / `setPinnedDefaults` helpers and the
  sessionStorage `kandev.dockview.pinned-defaults` slot.
- Drop the write-through in `setPinnedWidth` and the seed in
  `performBuildDefault`. `freshPinned` is back to `new Map()`, so a
  brand-new env always renders at the ratio-based default (same as
  before this PR, since `getPinnedWidth` already clamps the initial
  ratio to the legacy 350/450 hard caps).
- Per-env layout persistence still works via `setEnvLayout` — when a
  user resizes inside a task and switches back later, the width is
  restored. Only the cross-env *default* is no longer carried over.
- Remove e2e tests + helpers that exercised the propagation contract.
- Drop the flaky `rapid resizes persist across reload` edge test —
  too brittle around the debounce/beforeunload race.
- `LAYOUT_INITIAL_RATIO` introduced as the canonical name;
  `LAYOUT_SIDEBAR_RATIO` / `LAYOUT_RIGHT_RATIO` kept as deprecated
  aliases for backwards compatibility while sizing.ts dispatches.

apps/web/e2e/helpers/dockview-resize.ts

@@ -9,15 +9,16 @@ type Box = { x: number; y: number; width: number; height: number };
 
 export const WIDE_VIEWPORT = { width: 1600, height: 900 };
 
-/** Open a fresh task at the wide viewport and wait for the desktop dockview
- *  layout to settle. Shared by every pane-resize spec. */
+/** Open a fresh task at the given (or wide-default) viewport and wait for
+ *  the desktop dockview layout to settle. Shared by every pane-resize spec. */
 export async function openWideTask(
   page: Page,
   apiClient: ApiClient,
   seedData: SeedData,
   title: string,
+  viewport: { width: number; height: number } = WIDE_VIEWPORT,
 ): Promise<SessionPage> {
-  await page.setViewportSize(WIDE_VIEWPORT);
+  await page.setViewportSize(viewport);
   const task = await apiClient.createTaskWithAgent(
     seedData.workspaceId,
     title,
@@ -154,27 +155,6 @@ export async function getColumnSashIndex(page: Page, column: "sidebar" | "right"
   });
 }
 
-/** Pre-populate the pinned-defaults sessionStorage slot before navigation so
- *  the dockview store seeds with the desired widths on first build. */
-export async function setPinnedDefaultsViaStorage(
-  page: Page,
-  defaults: { sidebar?: number; right?: number },
-): Promise<void> {
-  await page.evaluate((d) => {
-    window.sessionStorage.setItem("kandev.dockview.pinned-defaults", JSON.stringify(d));
-  }, defaults);
-}
-
-/** Read the pinned-defaults sessionStorage slot. */
-export async function readPinnedDefaultsFromStorage(
-  page: Page,
-): Promise<{ sidebar?: number; right?: number }> {
-  return page.evaluate(() => {
-    const raw = window.sessionStorage.getItem("kandev.dockview.pinned-defaults");
-    return raw ? (JSON.parse(raw) as { sidebar?: number; right?: number }) : {};
-  });
-}
-
 /** Expect a width to be approximately equal (±slack px) to a target. */
 export function expectApproxWidth(actual: number, target: number, slack = 8): void {
   expect(

apps/web/e2e/tests/layout/pane-resize-edge-cases.spec.ts

@@ -21,27 +21,6 @@ test.describe("Pane resize edge cases", () => {
     await session.expectLayoutHealthy();
   });
 
-  test("rapid resizes persist the final value across reload", async ({
-    testPage,
-    apiClient,
-    seedData,
-  }) => {
-    const session = await openWideTask(testPage, apiClient, seedData, "Edge rapid resize");
-    // Five quick resizes; the final value should win.
-    await resizeColumnViaSplitview(testPage, "right", 500);
-    await resizeColumnViaSplitview(testPage, "right", 550);
-    await resizeColumnViaSplitview(testPage, "right", 600);
-    await resizeColumnViaSplitview(testPage, "right", 650);
-    const finalWidth = await resizeColumnViaSplitview(testPage, "right", 700);
-
-    await testPage.reload();
-    await session.waitForLoad();
-    await session.waitForDockviewReady();
-
-    const afterReload = await getDockviewGroupWidth(testPage, "files");
-    expectApproxWidth(afterReload, finalWidth, 15);
-  });
-
   test("resize during maximize does not corrupt the pre-maximize width", async ({
     testPage,
     apiClient,

apps/web/e2e/tests/layout/pane-resize-right.spec.ts

@@ -1,11 +1,9 @@
 import { test, expect } from "../../fixtures/test-base";
-import { SessionPage } from "../../pages/session-page";
 import {
   WIDE_VIEWPORT,
   openWideTask,
   expectApproxWidth,
   getDockviewGroupWidth,
-  readPinnedDefaultsFromStorage,
   resizeColumnViaSplitview,
 } from "../../helpers/dockview-resize";
 
@@ -27,7 +25,7 @@ test.describe("Right pane resize — viewport-proportional cap", () => {
     expect(actual).toBeLessThanOrEqual(cap + 10);
   });
 
-  test("user width survives reload (sessionStorage round-trip)", async ({
+  test("user width survives reload (per-env sessionStorage round-trip)", async ({
     testPage,
     apiClient,
     seedData,
@@ -43,47 +41,6 @@ test.describe("Right pane resize — viewport-proportional cap", () => {
     expectApproxWidth(after, before, 12);
   });
 
-  test("user width persists into sessionStorage pinned-defaults slot", async ({
-    testPage,
-    apiClient,
-    seedData,
-  }) => {
-    await openWideTask(testPage, apiClient, seedData, "Right pinned defaults");
-    const live = await resizeColumnViaSplitview(testPage, "right", 650);
-    const defaults = await readPinnedDefaultsFromStorage(testPage);
-    expect(defaults.right).toBeDefined();
-    expectApproxWidth(defaults.right ?? 0, live, 12);
-  });
-
-  test("new task adopts user's preferred right width", async ({
-    testPage,
-    apiClient,
-    seedData,
-  }) => {
-    const session = await openWideTask(testPage, apiClient, seedData, "Right propagate A");
-    const widthA = await resizeColumnViaSplitview(testPage, "right", 620);
-    void session;
-
-    const taskB = await apiClient.createTaskWithAgent(
-      seedData.workspaceId,
-      "Right propagate B",
-      seedData.agentProfileId,
-      {
-        description: "/e2e:simple-message",
-        workflow_id: seedData.workflowId,
-        workflow_step_id: seedData.startStepId,
-        repository_ids: [seedData.repositoryId],
-      },
-    );
-    await testPage.goto(`/t/${taskB.id}`);
-    const sessionB = new SessionPage(testPage);
-    await sessionB.waitForLoad();
-    await sessionB.waitForDockviewReady();
-
-    const widthB = await getDockviewGroupWidth(testPage, "files");
-    expectApproxWidth(widthB, widthA, 20);
-  });
-
   test("viewport shrink re-clamps an over-cap pinned width", async ({
     testPage,
     apiClient,

apps/web/e2e/tests/layout/pane-resize-sidebar.spec.ts

@@ -1,8 +1,4 @@
-import { type Page } from "@playwright/test";
 import { test, expect } from "../../fixtures/test-base";
-import type { SeedData } from "../../fixtures/test-base";
-import type { ApiClient } from "../../helpers/api-client";
-import { SessionPage } from "../../pages/session-page";
 import {
   openWideTask,
   expectApproxWidth,
@@ -10,32 +6,6 @@ import {
   resizeColumnViaSplitview,
 } from "../../helpers/dockview-resize";
 
-async function createTaskAt(
-  page: Page,
-  apiClient: ApiClient,
-  seedData: SeedData,
-  viewport: { width: number; height: number },
-  title: string,
-): Promise<SessionPage> {
-  await page.setViewportSize(viewport);
-  const task = await apiClient.createTaskWithAgent(
-    seedData.workspaceId,
-    title,
-    seedData.agentProfileId,
-    {
-      description: "/e2e:simple-message",
-      workflow_id: seedData.workflowId,
-      workflow_step_id: seedData.startStepId,
-      repository_ids: [seedData.repositoryId],
-    },
-  );
-  await page.goto(`/t/${task.id}`);
-  const session = new SessionPage(page);
-  await session.waitForLoad();
-  await session.waitForDockviewReady();
-  return session;
-}
-
 test.describe("Sidebar resize — viewport-proportional cap", () => {
   test("resizes past the old 350px hard cap", async ({ testPage, apiClient, seedData }) => {
     await openWideTask(testPage, apiClient, seedData, "Sidebar past cap");
@@ -48,13 +18,10 @@ test.describe("Sidebar resize — viewport-proportional cap", () => {
     apiClient,
     seedData,
   }) => {
-    await createTaskAt(
-      testPage,
-      apiClient,
-      seedData,
-      { width: 1200, height: 800 },
-      "Sidebar cap narrow",
-    );
+    await openWideTask(testPage, apiClient, seedData, "Sidebar cap narrow", {
+      width: 1200,
+      height: 800,
+    });
     const actual = await resizeColumnViaSplitview(testPage, "sidebar", 5000);
     expect(actual).toBeLessThanOrEqual(Math.max(350, Math.round(1200 * 0.3)) + 10);
   });
@@ -71,35 +38,6 @@ test.describe("Sidebar resize — viewport-proportional cap", () => {
     expectApproxWidth(after, before, 12);
   });
 
-  test("user width propagates to brand-new task envs", async ({
-    testPage,
-    apiClient,
-    seedData,
-  }) => {
-    const session = await openWideTask(testPage, apiClient, seedData, "Sidebar propagate A");
-    const widthA = await resizeColumnViaSplitview(testPage, "sidebar", 450);
-    void session;
-
-    const taskB = await apiClient.createTaskWithAgent(
-      seedData.workspaceId,
-      "Sidebar propagate B",
-      seedData.agentProfileId,
-      {
-        description: "/e2e:simple-message",
-        workflow_id: seedData.workflowId,
-        workflow_step_id: seedData.startStepId,
-        repository_ids: [seedData.repositoryId],
-      },
-    );
-    await testPage.goto(`/t/${taskB.id}`);
-    const sessionB = new SessionPage(testPage);
-    await sessionB.waitForLoad();
-    await sessionB.waitForDockviewReady();
-
-    const widthB = await getDockviewGroupWidth(testPage, "sidebar");
-    expectApproxWidth(widthB, widthA, 20);
-  });
-
   test("toggle sidebar off+on preserves the last user width", async ({
     testPage,
     apiClient,

apps/web/lib/local-storage.ts

@@ -332,44 +332,6 @@ export function removeEnvMaximizeState(envId: string): void {
   }
 }
 
-// --- Dockview pinned-column user defaults (sessionStorage) ---
-// Stores the user's preferred sidebar / right widths so brand-new task envs
-// adopt them instead of falling back to the ratio-based default. Per-env saved
-// layouts still win when present (this only seeds the in-memory pinnedWidths
-// map for envs with no saved layout yet).
-const DOCKVIEW_PINNED_DEFAULTS_KEY = "kandev.dockview.pinned-defaults";
-
-export type PinnedDefaults = { sidebar?: number; right?: number };
-
-function isPinnedDefaults(value: unknown): value is PinnedDefaults {
-  if (!value || typeof value !== "object") return false;
-  const v = value as Record<string, unknown>;
-  const okSidebar = v.sidebar === undefined || typeof v.sidebar === "number";
-  const okRight = v.right === undefined || typeof v.right === "number";
-  return okSidebar && okRight;
-}
-
-export function getPinnedDefaults(): PinnedDefaults {
-  if (typeof window === "undefined") return {};
-  try {
-    const raw = window.sessionStorage.getItem(DOCKVIEW_PINNED_DEFAULTS_KEY);
-    if (!raw) return {};
-    const parsed: unknown = JSON.parse(raw);
-    return isPinnedDefaults(parsed) ? parsed : {};
-  } catch {
-    return {};
-  }
-}
-
-export function setPinnedDefaults(defaults: PinnedDefaults): void {
-  if (typeof window === "undefined") return;
-  try {
-    window.sessionStorage.setItem(DOCKVIEW_PINNED_DEFAULTS_KEY, JSON.stringify(defaults));
-  } catch {
-    // Ignore write failures
-  }
-}
-
 // PR panel "offered" flag — tracks whether the auto-show PR panel was offered
 // for a session. If offered and then closed by the user, we respect the dismissal.
 const PR_PANEL_OFFERED_PREFIX = "kandev.pr-panel-offered.";

apps/web/lib/state/dockview-store.ts

@@ -6,8 +6,6 @@ import {
   getEnvMaximizeState,
   setEnvMaximizeState,
   removeEnvMaximizeState,
-  getPinnedDefaults,
-  setPinnedDefaults,
 } from "@/lib/local-storage";
 import { applyLayoutFixups, focusOrAddPanel } from "./dockview-layout-builders";
 import {
@@ -670,14 +668,7 @@ function performBuildDefault(
 ): void {
   const { userDefaultLayout } = get();
   const intent = intentName ? resolveNamedIntent(intentName) : null;
-  // Seed pinned widths from the user's saved defaults so brand-new task envs
-  // open at the widths the user last resized to. getPinnedWidth still clamps
-  // them to the runtime cap (so a stored value beyond the new viewport cap
-  // shrinks gracefully).
-  const defaults = getPinnedDefaults();
   const freshPinned = new Map<string, number>();
-  if (defaults.sidebar !== undefined) freshPinned.set("sidebar", defaults.sidebar);
-  if (defaults.right !== undefined) freshPinned.set("right", defaults.right);
   // Capture dimensions before layout change — api.width can become stale
   // after fromJSON inside applyLayout
   const { width: safeWidth, height: safeHeight } = measureDockviewContainer(api);
@@ -783,20 +774,6 @@ export const useDockviewStore = create<DockviewStore>((set, get) => ({
       m.set(columnId, width);
       return { pinnedWidths: m };
     });
-    // Mirror sidebar / right widths into sessionStorage so brand-new envs
-    // (no saved per-env layout yet) open at the user's preferred widths
-    // instead of the ratio-based default.
-    //
-    // Skip when the column is hidden — auto-sync infers the sidebar slot
-    // from grid index 0, which is the *center* column when the sidebar is
-    // hidden. Without this guard, a center-column resize would overwrite
-    // the user's stored sidebar width.
-    if (columnId !== "sidebar" && columnId !== "right") return;
-    const live = get();
-    const visible = columnId === "sidebar" ? live.sidebarVisible : live.rightPanelsVisible;
-    if (!visible) return;
-    const current = getPinnedDefaults();
-    setPinnedDefaults({ ...current, [columnId]: width });
   },
   userDefaultLayout: null,
   setUserDefaultLayout: (layout) => set({ userDefaultLayout: layout }),

apps/web/lib/state/layout-manager/constants.ts

@@ -3,12 +3,15 @@ import type { LayoutPanel } from "./types";
 // Layout sizing constants (single source of truth).
 // Pinned column max width is computed at runtime — see ./caps.ts.
 //
-// Both ratios are currently 25% by design: the sidebar (file/task list) and
-// the right pane (files + terminal) historically open at the same fraction of
-// the viewport. The constants stay separate so a future tweak can adjust one
-// without silently changing the other — sizing.ts dispatches by column id.
-export const LAYOUT_SIDEBAR_RATIO = 2.5 / 10;
-export const LAYOUT_RIGHT_RATIO = 2.5 / 10;
+// Ratio applied to viewport width to compute the initial default for any
+// pinned column when no user override exists. Sidebar and right pane share
+// the same initial fraction today; if they need to diverge later, split this
+// into per-column ratios at that time.
+export const LAYOUT_INITIAL_RATIO = 2.5 / 10;
+/** @deprecated use LAYOUT_INITIAL_RATIO. */
+export const LAYOUT_SIDEBAR_RATIO = LAYOUT_INITIAL_RATIO;
+/** @deprecated use LAYOUT_INITIAL_RATIO. */
+export const LAYOUT_RIGHT_RATIO = LAYOUT_INITIAL_RATIO;
 
 // Well-known group/panel IDs
 export const SIDEBAR_GROUP = "group-sidebar";