diff --git a/tests/e2e/AGENTS.md b/tests/e2e/AGENTS.md
index 1129f5c..20f9161 100644
--- a/tests/e2e/AGENTS.md
+++ b/tests/e2e/AGENTS.md
@@ -13,6 +13,8 @@
 
 ## Synchronization
 
+- Server-rendered visibility does not prove hydration. Call `waitForDashboardReady(page)` before dashboard input, keyboard/focus behavior, or client-router interaction after a full navigation or reload. Shared interaction helpers may own this wait. Preserve deliberate pre-hydration assertions and server-rendered-only checks.
+
 - Prefer route barriers (`page.route`, `route.fetch`, `route.fulfill`) and `Promise.withResolvers()` over sleeps.
 - Match API waits by HTTP method plus exact absolute URL, especially for period/date/history race tests.
 - Verify state both while a request is blocked and after it is released.
diff --git a/tests/e2e/dashboard-calendar.spec.ts b/tests/e2e/dashboard-calendar.spec.ts
index cdbd84b..38158d0 100644
--- a/tests/e2e/dashboard-calendar.spec.ts
+++ b/tests/e2e/dashboard-calendar.spec.ts
@@ -1,7 +1,12 @@
 import { expect, test } from "@playwright/test";
 import { configureDashboardDayEntryE2E } from "./dashboard-day-entry-helpers";
 import { seedPeriod } from "./helpers/db";
-import { addDays, getBaseUrl, getCurrentJstDate } from "./dashboard-shared";
+import {
+  addDays,
+  getBaseUrl,
+  getCurrentJstDate,
+  waitForDashboardReady,
+} from "./dashboard-shared";
 
 configureDashboardDayEntryE2E();
 
@@ -16,6 +21,7 @@ test("moves one roving calendar focus across months with keyboard", async ({
     budgetYen: 120000,
   });
   await page.goto(`${getBaseUrl()}/?periodId=p-calendar-keys`);
+  await waitForDashboardReady(page);
 
   const januaryEnd = page.getByTestId("calendar-day-2026-01-31");
   const februaryStart = page.getByTestId("calendar-day-2026-02-01");
@@ -77,6 +83,7 @@ test("calendar handoff opens the focused date once with Enter and retains select
     budgetYen: 120000,
   });
   await page.goto(`${getBaseUrl()}/?periodId=p-calendar-keys`);
+  await waitForDashboardReady(page);
 
   const date = "2026-02-01";
   const day = page.getByTestId(`calendar-day-${date}`);
@@ -114,6 +121,7 @@ test("calendar handoff opens the focused date once with Space", async ({
     budgetYen: 120000,
   });
   await page.goto(`${getBaseUrl()}/?periodId=p-calendar-keys`);
+  await waitForDashboardReady(page);
 
   const date = "2026-02-01";
   const day = page.getByTestId(`calendar-day-${date}`);
@@ -150,6 +158,7 @@ test("keyboard keeps disabled calendar dates focusable without opening history",
     budgetYen: 120000,
   });
   await page.goto(`${getBaseUrl()}/?periodId=p-calendar-current`);
+  await waitForDashboardReady(page);
 
   const periodSummaryBarrier = Promise.withResolvers<void>();
   const nextSummaryUrl = `${getBaseUrl()}/api/periods/p-calendar-next`;
@@ -213,6 +222,7 @@ test("keeps selection separate from keyboard focus and resets it for another per
     budgetYen: 120000,
   });
   await page.goto(`${getBaseUrl()}/?periodId=p-calendar-current`);
+  await waitForDashboardReady(page);
 
   const todayDay = page.getByTestId(`calendar-day-${today}`);
   const tomorrowDay = page.getByTestId(`calendar-day-${addDays(today, 1)}`);
@@ -257,6 +267,7 @@ test("keeps future allowance unchanged while future calendar input remains avail
     budgetYen: 90000,
   });
   await page.goto(`${getBaseUrl()}/?periodId=p-calendar-future`);
+  await waitForDashboardReady(page);
 
   const futureDay = page.getByTestId(`calendar-day-${futureStart}`);
   await expect(page.getByTestId("today-food-allowance")).toContainText("0 円");
@@ -279,6 +290,7 @@ test("blocks calendar activation while a period save is in flight, then restores
     budgetYen: 120000,
   });
   await page.goto(`${getBaseUrl()}/?periodId=p-calendar-save`);
+  await waitForDashboardReady(page);
 
   const saveBarrier = Promise.withResolvers<void>();
   const periodUrl = `${getBaseUrl()}/api/periods/p-calendar-save`;
@@ -340,6 +352,7 @@ test("keeps the calendar inside every supported viewport without clipping state
     ],
   });
   await page.goto(`${getBaseUrl()}/?periodId=p-calendar-responsive`);
+  await waitForDashboardReady(page);
   const todayDay = page.getByTestId(`calendar-day-${today}`);
   await todayDay.click();
   await page
diff --git a/tests/e2e/dashboard-create-period.spec.ts b/tests/e2e/dashboard-create-period.spec.ts
index 760534e..55a5f4f 100644
--- a/tests/e2e/dashboard-create-period.spec.ts
+++ b/tests/e2e/dashboard-create-period.spec.ts
@@ -5,6 +5,7 @@ import {
   getBaseUrl,
   getCurrentJstDate,
   resetTestData,
+  waitForDashboardReady,
 } from "./dashboard-shared";
 
 test.describe.configure({ mode: "serial", timeout: 120_000 });
@@ -24,6 +25,7 @@ for (const failureStage of ["summary", "list"] as const) {
     let posts = 0;
     let gets = 0;
     await page.goto(getBaseUrl());
+    await waitForDashboardReady(page);
     page.on("request", (request) => {
       if (request.method() === "POST") posts += 1;
     });
@@ -97,6 +99,7 @@ for (const variant of ["initial", "additional"] as const) {
       });
     }
     await page.goto(getBaseUrl());
+    await waitForDashboardReady(page);
     if (variant === "additional") {
       await page.getByText("次の予算期間を作成する").click();
     }
@@ -156,6 +159,7 @@ test("guards duplicate creation through a held POST and list GET", async ({
   let posts = 0;
   let gets = 0;
   await page.goto(getBaseUrl());
+  await waitForDashboardReady(page);
   await page.route(`${getBaseUrl()}/api/periods`, async (route) => {
     if (route.request().method() === "POST") {
       posts += 1;
@@ -221,6 +225,7 @@ test("additional recovery does not reopen or steal focus after closing during re
   let gets = 0;
   let posts = 0;
   await page.goto(getBaseUrl());
+  await waitForDashboardReady(page);
   page.on("request", (request) => {
     if (request.method() === "POST") posts += 1;
   });
@@ -280,6 +285,7 @@ test("validates fields in form order and submits corrected drafts with Enter", a
   const today = getCurrentJstDate();
   const writes: string[] = [];
   await page.goto(getBaseUrl());
+  await waitForDashboardReady(page);
   page.on("request", (request) => {
     if (["POST", "PUT"].includes(request.method())) writes.push(request.url());
   });
@@ -326,6 +332,7 @@ test("initial cancel restores defaults and clears field errors without writing",
 }, testInfo) => {
   const today = getCurrentJstDate();
   await page.goto(getBaseUrl());
+  await waitForDashboardReady(page);
   const writes: string[] = [];
   page.on("request", (request) => {
     if (["POST", "PUT"].includes(request.method())) writes.push(request.url());
@@ -372,6 +379,7 @@ test("additional cancel closes the form and keeps drafts while clearing server f
     budgetYen: 120000,
   });
   await page.goto(getBaseUrl());
+  await waitForDashboardReady(page);
   const opener = page.getByText("次の予算期間を作成する");
   await opener.click();
   await page.getByLabel("期間ID", { exact: true }).fill("p-retained");
diff --git a/tests/e2e/dashboard-day-entry-failure-handling.spec.ts b/tests/e2e/dashboard-day-entry-failure-handling.spec.ts
index 8ed30d9..77fdeff 100644
--- a/tests/e2e/dashboard-day-entry-failure-handling.spec.ts
+++ b/tests/e2e/dashboard-day-entry-failure-handling.spec.ts
@@ -3,7 +3,7 @@ import {
   configureDashboardDayEntryE2E,
   seedCurrentPeriod,
 } from "./dashboard-day-entry-helpers";
-import { getBaseUrl } from "./dashboard-shared";
+import { getBaseUrl, waitForDashboardReady } from "./dashboard-shared";
 
 configureDashboardDayEntryE2E();
 
@@ -14,6 +14,7 @@ test("rejects malformed day-entry yen values before requests", async ({
   const { periodId, todayDate } = await seedCurrentPeriod(request);
 
   await page.goto(`${getBaseUrl()}/?periodId=${encodeURIComponent(periodId)}`);
+  await waitForDashboardReady(page);
   let addRequestCount = 0;
   await page.route(
     `**/api/periods/${periodId}/days/${todayDate}/add`,
@@ -71,6 +72,7 @@ test("shows save error and keeps input on failed day entry update", async ({
   const { periodId, todayDate } = await seedCurrentPeriod(request);
 
   await page.goto(`${getBaseUrl()}/?periodId=${encodeURIComponent(periodId)}`);
+  await waitForDashboardReady(page);
   const retryBarrier = Promise.withResolvers<void>();
   let addRequestCount = 0;
   await page.route(
@@ -136,6 +138,7 @@ test("shows history load error while keeping the day entry modal usable", async
   const { periodId, todayDate } = await seedCurrentPeriod(request);
 
   await page.goto(`${getBaseUrl()}/?periodId=${encodeURIComponent(periodId)}`);
+  await waitForDashboardReady(page);
   await page.route(
     `**/api/periods/${periodId}/days/${todayDate}/history`,
     async (route) => {
diff --git a/tests/e2e/dashboard-day-entry-surface.spec.ts b/tests/e2e/dashboard-day-entry-surface.spec.ts
index d861f66..717b446 100644
--- a/tests/e2e/dashboard-day-entry-surface.spec.ts
+++ b/tests/e2e/dashboard-day-entry-surface.spec.ts
@@ -5,7 +5,7 @@ import {
   openDayEntryAndWaitForHistory,
   seedCurrentPeriod,
 } from "./dashboard-day-entry-helpers";
-import { getBaseUrl } from "./dashboard-shared";
+import { getBaseUrl, waitForDashboardReady } from "./dashboard-shared";
 
 configureDashboardDayEntryE2E();
 
@@ -190,6 +190,7 @@ test("returns focus to the calendar origin and announces an accepted save", asyn
 
   await page.setViewportSize({ width: 1280, height: 900 });
   await page.goto(`${getBaseUrl()}/?periodId=${encodeURIComponent(periodId)}`);
+  await waitForDashboardReady(page);
   await origin.focus();
   const initialHistoryResponse = page.waitForResponse(
     (response) =>
@@ -244,6 +245,7 @@ test("falls back to the calendar heading when its origin is removed", async ({
   const { periodId, todayDate } = await seedCurrentPeriod(request);
   const origin = page.getByTestId(`calendar-day-${todayDate}`);
   await page.goto(`${getBaseUrl()}/?periodId=${encodeURIComponent(periodId)}`);
+  await waitForDashboardReady(page);
   await origin.focus();
   await origin.press("Enter");
   const modal = page.getByTestId("day-entry-modal");
diff --git a/tests/e2e/dashboard-history-surface.spec.ts b/tests/e2e/dashboard-history-surface.spec.ts
index 11bfc12..5fc8732 100644
--- a/tests/e2e/dashboard-history-surface.spec.ts
+++ b/tests/e2e/dashboard-history-surface.spec.ts
@@ -9,7 +9,7 @@ import {
   configureDashboardDayEntryE2E,
   seedCurrentPeriod,
 } from "./dashboard-day-entry-helpers";
-import { getBaseUrl } from "./dashboard-shared";
+import { getBaseUrl, waitForDashboardReady } from "./dashboard-shared";
 
 configureDashboardDayEntryE2E();
 
@@ -31,6 +31,7 @@ async function openHistoryWithEntries(
   periodId: string,
   date: string,
 ): Promise<Locator> {
+  await waitForDashboardReady(page);
   const historyUrl = new URL(
     `/api/periods/${encodeURIComponent(periodId)}/days/${encodeURIComponent(date)}/history`,
     getBaseUrl(),
@@ -61,6 +62,7 @@ test("keeps loading and empty history states exclusive", async ({
     await route.continue();
   });
   await page.goto(`${getBaseUrl()}/?periodId=${encodeURIComponent(periodId)}`);
+  await waitForDashboardReady(page);
   await page.getByTestId(`calendar-day-${todayDate}`).click();
   await historyRequested.promise;
 
@@ -122,6 +124,7 @@ test("keeps retry focused through a failed history GET and moves it after succes
     });
   });
   await page.goto(`${getBaseUrl()}/?periodId=${encodeURIComponent(periodId)}`);
+  await waitForDashboardReady(page);
   await page.getByTestId(`calendar-day-${todayDate}`).click();
 
   const modal = page.getByTestId("day-entry-modal");
@@ -171,6 +174,7 @@ test("loads a readable history row with wrapping memo", async ({
   );
   expect(response.ok()).toBe(true);
   await page.goto(`${getBaseUrl()}/?periodId=${encodeURIComponent(periodId)}`);
+  await waitForDashboardReady(page);
   await page.getByTestId(`calendar-day-${todayDate}`).click();
 
   const modal = page.getByTestId("day-entry-modal");
diff --git a/tests/e2e/dashboard-hydration.spec.ts b/tests/e2e/dashboard-hydration.spec.ts
index 5dfafc3..3d49067 100644
--- a/tests/e2e/dashboard-hydration.spec.ts
+++ b/tests/e2e/dashboard-hydration.spec.ts
@@ -1,4 +1,4 @@
-import { expect, test } from "@playwright/test";
+import { expect, test, type Page } from "@playwright/test";
 import {
   getBaseUrl,
   resetTestData,
@@ -8,16 +8,14 @@ import {
   assertExactDialog,
   assertUnchangedPair,
   proposeBoundaryChange,
+  readPeriod,
+  readPeriodList,
   seedBoundaryPair,
   target,
 } from "./period-boundary-confirmation-helpers";
+import { seedPeriod } from "./helpers/db";
 
-test("waits for hydration before editing server-rendered settings", async ({
-  page,
-  request,
-}) => {
-  await resetTestData(request);
-  await seedBoundaryPair(request);
+async function delayClientEntry(page: Page) {
   const clientRequested = Promise.withResolvers<void>();
   const releaseClient = Promise.withResolvers<void>();
   const clientEntry = /\/_app\/immutable\/entry\/start\.[^/]+\.js$/;
@@ -26,6 +24,24 @@ test("waits for hydration before editing server-rendered settings", async ({
     await releaseClient.promise;
     await route.continue();
   });
+  return {
+    clientRequested,
+    releaseClient,
+    dispose: async () => {
+      releaseClient.resolve();
+      await page.unroute(clientEntry);
+    },
+  };
+}
+
+test("waits for hydration before editing server-rendered settings", async ({
+  page,
+  request,
+}) => {
+  await resetTestData(request);
+  await seedBoundaryPair(request);
+  const { clientRequested, releaseClient, dispose } =
+    await delayClientEntry(page);
 
   try {
     await page.goto(`${getBaseUrl()}/?periodId=${target.periodId}`, {
@@ -46,7 +62,141 @@ test("waits for hydration before editing server-rendered settings", async ({
     await expect(page.getByLabel("期間予算 (円)")).toHaveValue("123456");
     await assertUnchangedPair(request);
   } finally {
+    await dispose();
+  }
+});
+
+for (const navigation of ["navigation", "reload"] as const) {
+  test(`waits for hydration after ${navigation} before validating and submitting an initial period`, async ({
+    page,
+    request,
+  }) => {
+    await resetTestData(request);
+    if (navigation === "reload") {
+      await page.goto(getBaseUrl());
+      await waitForDashboardReady(page);
+    }
+    const { clientRequested, releaseClient, dispose } =
+      await delayClientEntry(page);
+    const writes: string[] = [];
+    page.on("request", (request) => {
+      if (["POST", "PUT"].includes(request.method()))
+        writes.push(request.url());
+    });
+
+    try {
+      if (navigation === "reload") {
+        await page.reload({ waitUntil: "domcontentloaded" });
+      } else {
+        await page.goto(getBaseUrl(), { waitUntil: "domcontentloaded" });
+      }
+      await clientRequested.promise;
+      const start = page.getByTestId("initial-period-range-start");
+      const id = page.getByLabel("期間ID", { exact: true });
+      await expect(start).toBeVisible();
+      await expect(start).toBeEnabled();
+      await expect(page.getByRole("main")).toHaveAttribute("aria-busy", "true");
+
+      const ready = waitForDashboardReady(page);
+      releaseClient.resolve();
+      await ready;
+      await start.fill("2026-09-");
+      await page.getByTestId("initial-period-range-end").fill("2026-09-30");
+      await page.getByLabel("新規予算額 (円)").fill("130000");
+      await id.fill("p-hydrated-initial");
+      await page
+        .getByRole("button", { name: "期間を作成", exact: true })
+        .click();
+      await expect(start).toBeFocused();
+      await expect(start).toHaveValue("2026-09-");
+      await expect(start).toHaveAttribute("aria-invalid", "true");
+      await expect(start).toHaveAccessibleDescription(/有効な開始日/);
+      expect(writes).toEqual([]);
+      expect(await readPeriodList(request)).toEqual([]);
+
+      await start.fill("2026-09-01");
+      await expect(start).toHaveAttribute("aria-invalid", "false");
+      await id.press("Enter");
+      await expect(page.getByTestId("period-select")).toHaveValue(
+        "p-hydrated-initial",
+      );
+      await expect(page.locator("#selected-period-heading")).toBeFocused();
+      expect(writes).toEqual([`${getBaseUrl()}/api/periods`]);
+      expect(await readPeriod(request, "p-hydrated-initial")).toMatchObject({
+        startDate: "2026-09-01",
+        endDate: "2026-09-30",
+        budgetYen: 130000,
+      });
+    } finally {
+      await dispose();
+    }
+  });
+}
+
+test("waits for hydration before calendar keys and additional period creation", async ({
+  page,
+  request,
+}) => {
+  await resetTestData(request);
+  await seedPeriod(request, getBaseUrl(), {
+    periodId: "p-hydrated-calendar",
+    startDate: "2026-01-20",
+    endDate: "2026-02-10",
+    budgetYen: 120000,
+  });
+  const { clientRequested, releaseClient, dispose } =
+    await delayClientEntry(page);
+
+  try {
+    await page.goto(`${getBaseUrl()}/?periodId=p-hydrated-calendar`, {
+      waitUntil: "domcontentloaded",
+    });
+    await clientRequested.promise;
+    const januaryEnd = page.getByTestId("calendar-day-2026-01-31");
+    const februaryStart = page.getByTestId("calendar-day-2026-02-01");
+    const additional = page.getByTestId("create-period-panel");
+    await expect(januaryEnd).toBeVisible();
+    await expect(januaryEnd).toBeEnabled();
+    await expect(additional.locator("summary")).toBeVisible();
+    await expect(page.getByRole("main")).toHaveAttribute("aria-busy", "true");
+
+    const ready = waitForDashboardReady(page);
     releaseClient.resolve();
-    await page.unroute(clientEntry);
+    await ready;
+    await januaryEnd.focus();
+    await januaryEnd.press("ArrowRight");
+    await expect(februaryStart).toBeFocused();
+    await expect(
+      page.locator('[data-testid^="calendar-day-"][tabindex="0"]'),
+    ).toHaveCount(1);
+    await februaryStart.press("Enter");
+    const modal = page.getByTestId("day-entry-modal");
+    await expect(modal).toContainText("対象日: 2026-02-01");
+    await modal.getByRole("button", { name: "閉じる" }).click();
+    await expect(modal).not.toBeVisible();
+    await expect(februaryStart).toBeFocused();
+    await expect(februaryStart).toHaveAttribute("aria-pressed", "true");
+
+    await additional.locator("summary").click();
+    await additional
+      .getByTestId("create-period-range-start")
+      .fill("2026-02-11");
+    await additional.getByTestId("create-period-range-end").fill("2026-03-10");
+    await additional.getByLabel("新規予算額 (円)").fill("90000");
+    await additional
+      .getByLabel("期間ID", { exact: true })
+      .fill("p-hydrated-next");
+    await additional.getByLabel("期間ID", { exact: true }).press("Enter");
+    await expect(page.getByTestId("period-select")).toHaveValue(
+      "p-hydrated-next",
+    );
+    await expect(page.locator("#selected-period-heading")).toBeFocused();
+    expect(await readPeriod(request, "p-hydrated-next")).toMatchObject({
+      startDate: "2026-02-11",
+      endDate: "2026-03-10",
+      budgetYen: 90000,
+    });
+  } finally {
+    await dispose();
   }
 });
diff --git a/tests/e2e/dashboard-integrated-flow.spec.ts b/tests/e2e/dashboard-integrated-flow.spec.ts
index 39fdca5..b0dcd67 100644
--- a/tests/e2e/dashboard-integrated-flow.spec.ts
+++ b/tests/e2e/dashboard-integrated-flow.spec.ts
@@ -3,7 +3,12 @@ import {
   configureDashboardDayEntryE2E,
   saveDayEntrySuccessfully,
 } from "./dashboard-day-entry-helpers";
-import { addDays, getBaseUrl, getCurrentJstDate } from "./dashboard-shared";
+import {
+  addDays,
+  getBaseUrl,
+  getCurrentJstDate,
+  waitForDashboardReady,
+} from "./dashboard-shared";
 
 configureDashboardDayEntryE2E();
 
@@ -31,6 +36,7 @@ for (const viewport of [
     page.on("pageerror", (error) => errors.push(error.message));
 
     await page.goto(`${getBaseUrl()}/`);
+    await waitForDashboardReady(page);
     await expect(page.getByTestId("create-period-panel")).toBeVisible();
     await page.getByLabel("期間ID", { exact: true }).fill(periodId);
     await page.getByTestId("initial-period-range-start").fill(start);
@@ -180,6 +186,7 @@ for (const viewport of [
     await expect(dialog).toHaveCount(0);
     await expect(currentRange).toHaveText(`${start} - ${today}`);
     await page.reload();
+    await waitForDashboardReady(page);
     await expect(currentRange).toHaveText(`${start} - ${today}`);
     await expect(page.getByTestId("budget-value")).toContainText("130,000");
     await select.selectOption(nextId);
@@ -187,6 +194,7 @@ for (const viewport of [
       `${addDays(today, 1)} - ${extendedEnd}`,
     );
     await page.reload();
+    await waitForDashboardReady(page);
     await expect(select).toHaveValue(periodId);
     await select.selectOption(nextId);
     await expect(currentRange).toHaveText(
diff --git a/tests/e2e/dashboard-period-operation-state.spec.ts b/tests/e2e/dashboard-period-operation-state.spec.ts
index 74ff63f..9d3f1b9 100644
--- a/tests/e2e/dashboard-period-operation-state.spec.ts
+++ b/tests/e2e/dashboard-period-operation-state.spec.ts
@@ -1,5 +1,9 @@
 import { expect, test } from "@playwright/test";
-import { getBaseUrl, resetTestData } from "./dashboard-shared";
+import {
+  getBaseUrl,
+  resetTestData,
+  waitForDashboardReady,
+} from "./dashboard-shared";
 import { seedPeriod } from "./helpers/db";
 import {
   applyRange,
@@ -34,6 +38,7 @@ test.describe("independent period operations", () => {
   test.beforeEach(async ({ page, request }) => {
     await seedPeriod(request, getBaseUrl(), period);
     await page.goto(`${getBaseUrl()}/?periodId=${period.periodId}`);
+    await waitForDashboardReady(page);
     await openSettings(page);
   });
 
diff --git a/tests/e2e/dashboard-range-settings.spec.ts b/tests/e2e/dashboard-range-settings.spec.ts
index 37f907f..38addbd 100644
--- a/tests/e2e/dashboard-range-settings.spec.ts
+++ b/tests/e2e/dashboard-range-settings.spec.ts
@@ -5,7 +5,12 @@ import {
   type APIRequestContext,
 } from "@playwright/test";
 import { seedPeriod } from "./helpers/db";
-import { addDays, getBaseUrl, resetTestData } from "./dashboard-shared";
+import {
+  addDays,
+  getBaseUrl,
+  resetTestData,
+  waitForDashboardReady,
+} from "./dashboard-shared";
 import {
   holdResponse,
   waitForResponse,
@@ -30,6 +35,7 @@ async function openRange(page: Page, request: APIRequestContext) {
     budgetYen: 120000,
   });
   await page.goto(`${getBaseUrl()}/?periodId=${periodId}`);
+  await waitForDashboardReady(page);
   await page.getByText("期間の終了日や予算を変更する").click();
   const form = page.getByRole("form", { name: "期間設定", exact: true });
   return {
diff --git a/tests/e2e/dashboard-shell.spec.ts b/tests/e2e/dashboard-shell.spec.ts
index 6bceb75..0e0d95c 100644
--- a/tests/e2e/dashboard-shell.spec.ts
+++ b/tests/e2e/dashboard-shell.spec.ts
@@ -5,6 +5,7 @@ import {
   getBaseUrl,
   getCurrentJstDate,
   resetTestData,
+  waitForDashboardReady,
 } from "./dashboard-shared";
 
 test.beforeEach(async ({ request }) => {
@@ -61,6 +62,7 @@ test("shows shell regions in document order", async ({ page, request }) => {
 
 test("keeps empty and additional create bodies reachable", async ({ page }) => {
   await page.goto(getBaseUrl());
+  await waitForDashboardReady(page);
   await expect(page.locator("#empty-period-heading")).toBeVisible();
   await expect(page.getByLabel("期間ID")).toBeVisible();
   await page.getByLabel("期間ID").fill("p-shell-created");
@@ -89,6 +91,7 @@ test("keeps the selected summary while a failed selection is reported at the she
     budgetYen: 90000,
   });
   await page.goto(`${getBaseUrl()}/?periodId=p-shell-current`);
+  await waitForDashboardReady(page);
   const retryBarrier = Promise.withResolvers<void>();
   let futureGetCount = 0;
   const futureUrl = `${getBaseUrl()}/api/periods/p-shell-future`;
@@ -175,6 +178,7 @@ test("keeps the current draft while an exact period GET is loading", async ({
     budgetYen: 90000,
   });
   await page.goto(`${getBaseUrl()}/?periodId=p-shell-current`);
+  await waitForDashboardReady(page);
   await page.getByText("期間の終了日や予算を変更する").click();
   await page.getByLabel("期間予算 (円)").fill("130000");
 
@@ -221,6 +225,7 @@ test("keeps a failed additional create error visible while settings stay closed"
     budgetYen: 120000,
   });
   await page.goto(`${getBaseUrl()}/?periodId=p-shell-current`);
+  await waitForDashboardReady(page);
 
   const settings = page
     .getByText("期間の終了日や予算を変更する")
diff --git a/tests/e2e/dashboard.spec.ts b/tests/e2e/dashboard.spec.ts
index 78f2f9b..d04b20e 100644
--- a/tests/e2e/dashboard.spec.ts
+++ b/tests/e2e/dashboard.spec.ts
@@ -5,6 +5,7 @@ import {
   getBaseUrl,
   getCurrentJstDate,
   resetTestData,
+  waitForDashboardReady,
 } from "./dashboard-shared";
 
 test.describe.configure({ mode: "serial", timeout: 120_000 });
@@ -18,6 +19,7 @@ test("creates period", async ({ page }) => {
   const endDate = addDays(today, 29);
 
   await page.goto(`${getBaseUrl()}/`);
+  await waitForDashboardReady(page);
   await expect(page.getByTestId("create-period-panel")).toBeVisible();
   await expect(page.getByLabel("期間ID")).toBeVisible();
   await expect(page.getByLabel("新規予算額 (円)")).toBeVisible();
@@ -61,6 +63,7 @@ test("preserves manually edited create ID after applying range", async ({
   page.on("pageerror", (error) => pageErrors.push(error.message));
 
   await page.goto(`${getBaseUrl()}/`);
+  await waitForDashboardReady(page);
   await page.getByLabel("期間ID").fill(periodId);
   await page.getByTestId("initial-period-range-start").fill(today);
   await page.getByTestId("initial-period-range-end").fill(endDate);
@@ -108,6 +111,7 @@ test("updates period start and end dates from settings inputs", async ({
   });
 
   await page.goto(`${getBaseUrl()}/?periodId=${encodeURIComponent(periodId)}`);
+  await waitForDashboardReady(page);
   await expect(page.getByTestId("period-id")).toContainText(periodId);
   await page.getByText("期間の終了日や予算を変更する").click();
   await page.getByTestId("current-period-range-start").fill(updatedStartDate);
@@ -149,6 +153,7 @@ test("switches between current and future budget periods", async ({
   });
 
   await page.goto(`${getBaseUrl()}/`);
+  await waitForDashboardReady(page);
   await expect(page.getByTestId("period-id")).toContainText(currentPeriodId);
 
   await page.getByTestId("period-select").selectOption(futurePeriodId);
@@ -200,6 +205,7 @@ test("creates the next budget period from secondary settings", async ({
   });
 
   await page.goto(`${getBaseUrl()}/`);
+  await waitForDashboardReady(page);
   await expect(page.getByTestId("period-id")).toContainText(currentPeriodId);
   await page.getByText("次の予算期間を作成する").click();
   await page.getByLabel("期間ID").fill(nextPeriodId);
@@ -235,6 +241,7 @@ test("shows an error when shrinking a period would exclude saved entries", async
   });
 
   await page.goto(`${getBaseUrl()}/?periodId=${encodeURIComponent(periodId)}`);
+  await waitForDashboardReady(page);
   await page.getByText("期間の終了日や予算を変更する").click();
   await page.getByTestId("current-period-range-end").fill(invalidEndDate);
   await page.getByTestId("current-period-range-apply").click();
diff --git a/tests/e2e/framework-error-retry.spec.ts b/tests/e2e/framework-error-retry.spec.ts
index 4978fcd..e227d0c 100644
--- a/tests/e2e/framework-error-retry.spec.ts
+++ b/tests/e2e/framework-error-retry.spec.ts
@@ -1,5 +1,9 @@
 import { expect, test } from "@playwright/test";
-import { getBaseUrl, resetTestData } from "./dashboard-shared";
+import {
+  getBaseUrl,
+  resetTestData,
+  waitForDashboardReady,
+} from "./dashboard-shared";
 
 test("retries a framework page-load error without losing URL or focus", async ({
   page,
@@ -9,6 +13,7 @@ test("retries a framework page-load error without losing URL or focus", async ({
   const initialUrl = `${getBaseUrl()}/?periodId=before-retry`;
   const retryUrl = `${getBaseUrl()}/?periodId=after-retry&keep=1#empty-period-heading`;
   await page.goto(initialUrl);
+  await waitForDashboardReady(page);
   await expect(page.locator("#empty-period-heading")).toBeVisible();
 
   const releaseRetry = Promise.withResolvers<void>();
diff --git a/tests/e2e/period-range-picker.spec.ts b/tests/e2e/period-range-picker.spec.ts
index 8d9a792..eb806d8 100644
--- a/tests/e2e/period-range-picker.spec.ts
+++ b/tests/e2e/period-range-picker.spec.ts
@@ -1,6 +1,10 @@
 import { expect, test } from "@playwright/test";
 import { seedPeriod } from "./helpers/db";
-import { getBaseUrl, resetTestData } from "./dashboard-shared";
+import {
+  getBaseUrl,
+  resetTestData,
+  waitForDashboardReady,
+} from "./dashboard-shared";
 
 test.describe.configure({ mode: "serial", timeout: 120_000 });
 
@@ -20,6 +24,7 @@ test("raw input retains invalid text, associates errors, and makes no mutation",
   });
 
   await page.goto(`${getBaseUrl()}/?periodId=p-range-360`);
+  await waitForDashboardReady(page);
   await page.getByText("期間の終了日や予算を変更する").click();
 
   let mutationCount = 0;
@@ -104,6 +109,7 @@ test("calendar sync publishes a partial selection without retaining the old end"
   });
 
   await page.goto(`${getBaseUrl()}/?periodId=p-range-calendar-sync`);
+  await waitForDashboardReady(page);
   await page.getByText("期間の終了日や予算を変更する").click();
 
   const calendar = page.locator("[data-range-calendar-root]").first();
@@ -155,6 +161,7 @@ test("calendar starts a fresh range from invalid and reversed controlled raw val
   });
 
   await page.goto(`${getBaseUrl()}/?periodId=p-range-calendar-raw`);
+  await waitForDashboardReady(page);
   await page.getByText("期間の終了日や予算を変更する").click();
 
   const start = page.getByTestId("current-period-range-start");
@@ -204,6 +211,7 @@ test("calendar synchronizes a parent period reset without retaining its old rang
   });
 
   await page.goto(`${getBaseUrl()}/?periodId=p-range-calendar-reset-current`);
+  await waitForDashboardReady(page);
   await page.getByText("期間の終了日や予算を変更する").click();
 
   const calendar = page.locator("[data-range-calendar-root]").first();
@@ -241,6 +249,7 @@ test("calendar keyboard follows the manual inputs and updates the controlled ran
 
   await page.setViewportSize({ width: 1280, height: 800 });
   await page.goto(`${getBaseUrl()}/?periodId=p-range-calendar-keyboard`);
+  await waitForDashboardReady(page);
   await page.getByText("期間の終了日や予算を変更する").click();
 
   const start = page.getByTestId("current-period-range-start");
@@ -295,6 +304,7 @@ test("calendar disables its mouse and keyboard controls while a range save is he
   });
 
   await page.goto(`${getBaseUrl()}/?periodId=${periodId}`);
+  await waitForDashboardReady(page);
   await page.getByText("期間の終了日や予算を変更する").click();
 
   const periodUrl = `${getBaseUrl()}/api/periods/${periodId}`;
@@ -360,6 +370,7 @@ test("calendar keeps day controls usable on a mobile viewport", async ({
 
   await page.setViewportSize({ width: 375, height: 812 });
   await page.goto(`${getBaseUrl()}/?periodId=p-range-calendar-mobile`);
+  await waitForDashboardReady(page);
   await page.getByText("期間の終了日や予算を変更する").click();
 
   const day = page
@@ -386,6 +397,7 @@ test("create apply preserves raw drafts until valid and reaches both create POST
   request,
 }) => {
   await page.goto(getBaseUrl());
+  await waitForDashboardReady(page);
   const initialId = page.getByLabel("期間ID");
   const initialStart = page.getByTestId("initial-period-range-start");
   await page.getByTestId("initial-period-range-apply").click();
@@ -427,6 +439,7 @@ test("create apply preserves raw drafts until valid and reaches both create POST
     budgetYen: 120000,
   });
   await page.goto(getBaseUrl());
+  await waitForDashboardReady(page);
   await page.getByText("次の予算期間を作成する").click();
   const additionalId = page.getByLabel("期間ID");
   await additionalId.fill("custom-additional-id");