test: add Playwright e2e tests for rename tab feature

Tests double-click → inline edit → Enter saves, and Escape cancels.
Both tests pass with visual screenshot verification.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

e2e/rename-tab.spec.ts

@@ -0,0 +1,80 @@
+import { test, expect } from '@playwright/test'
+
+test('rename tab by double-clicking', async ({ page }) => {
+  await page.goto('/')
+  await page.waitForTimeout(2000)
+
+  // Screenshot initial state
+  await page.screenshot({ path: 'test-results/rename-01-initial.png', fullPage: true })
+
+  // Click a note in the list using text content
+  await page.getByText('Deprecated Workflow').first().click()
+  await page.waitForTimeout(500)
+
+  // Screenshot: note opened as tab
+  await page.screenshot({ path: 'test-results/rename-02-note-opened.png', fullPage: true })
+
+  // Find the tab title in the tab bar and double-click it
+  const tabTitle = page.locator('.group span.truncate').first()
+  await expect(tabTitle).toBeVisible({ timeout: 5000 })
+  const originalTitle = await tabTitle.textContent()
+  console.log(`Original title: "${originalTitle}"`)
+
+  await tabTitle.dblclick()
+  await page.waitForTimeout(300)
+
+  // Screenshot: editing mode
+  await page.screenshot({ path: 'test-results/rename-03-editing.png', fullPage: true })
+
+  // Verify input appeared
+  const editInput = page.locator('.group input')
+  await expect(editInput).toBeVisible({ timeout: 3000 })
+
+  // Type new name
+  await editInput.fill('Renamed Test Note')
+  await page.screenshot({ path: 'test-results/rename-04-typing.png', fullPage: true })
+
+  // Press Enter to save
+  await editInput.press('Enter')
+  await page.waitForTimeout(1000)
+
+  // Screenshot: after rename
+  await page.screenshot({ path: 'test-results/rename-05-saved.png', fullPage: true })
+
+  // Verify tab title changed
+  const newTabTitle = page.locator('.group span.truncate').first()
+  await expect(newTabTitle).toHaveText('Renamed Test Note')
+})
+
+test('cancel rename with Escape', async ({ page }) => {
+  await page.goto('/')
+  await page.waitForTimeout(2000)
+
+  // Open a note
+  await page.getByText('Deprecated Workflow').first().click()
+  await page.waitForTimeout(500)
+
+  const tabTitle = page.locator('.group span.truncate').first()
+  const originalTitle = await tabTitle.textContent()
+
+  // Double-click to edit
+  await tabTitle.dblclick()
+  await page.waitForTimeout(300)
+
+  const editInput = page.locator('.group input')
+  await expect(editInput).toBeVisible({ timeout: 3000 })
+
+  // Type something different
+  await editInput.fill('Will Be Cancelled')
+
+  // Press Escape to cancel
+  await editInput.press('Escape')
+  await page.waitForTimeout(300)
+
+  // Screenshot: after cancel
+  await page.screenshot({ path: 'test-results/rename-06-cancelled.png', fullPage: true })
+
+  // Verify title unchanged
+  const afterTitle = page.locator('.group span.truncate').first()
+  await expect(afterTitle).toHaveText(originalTitle!)
+})