fix: resolve mini navigation game name persistence across all routes

Add @nav parallel route slots for all major routes to prevent game names
from persisting when navigating between different sections of the app.

- Add @nav/page.tsx (home)
- Add @nav/create/page.tsx (create page)
- Add @nav/guide/page.tsx (guide page)
- Add @nav/games/page.tsx (games listing)
- Keep @nav/games/matching/page.tsx (Memory Pairs game)
- Keep @nav/games/memory-quiz/page.tsx (Memory Lightning game)
- Add comprehensive e2e test covering navigation persistence scenarios

All non-game routes return null (no game name in mini nav).
Only game routes show their specific game names.

Fixes issue where navigating Game → Guide → Games would show stale game name.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

apps/web/e2e/mini-nav-persistence.spec.ts

@@ -0,0 +1,111 @@
+import { test, expect } from '@playwright/test'
+
+test.describe('Mini Navigation Game Name Persistence', () => {
+  test('should not show game name when navigating back to games page from a specific game', async ({ page }) => {
+    // Override baseURL for this test to match running dev server
+    const baseURL = 'http://localhost:3000'
+
+    // Start at home page
+    await page.goto(baseURL)
+
+    // Navigate to games page - should not have game name in mini nav
+    await page.click('a[href="/games"]')
+    await page.waitForURL('/games')
+
+    // Check that mini nav doesn't show game name initially
+    const initialGameName = page.locator('[data-testid="mini-nav-game-name"]')
+    await expect(initialGameName).not.toBeVisible()
+
+    // Navigate to Memory Pairs game
+    await page.click('a[href="/games/matching"]')
+    await page.waitForURL('/games/matching')
+
+    // Verify game name appears in mini nav
+    const memoryPairsName = page.locator('text=🧩 Memory Pairs')
+    await expect(memoryPairsName).toBeVisible()
+
+    // Navigate back to games page using mini nav
+    await page.click('a[href="/games"]')
+    await page.waitForURL('/games')
+
+    // BUG: Game name should disappear but it persists
+    // This test should FAIL initially, demonstrating the bug
+    await expect(memoryPairsName).not.toBeVisible()
+
+    // Also test with Memory Lightning game
+    await page.click('a[href="/games/memory-quiz"]')
+    await page.waitForURL('/games/memory-quiz')
+
+    // Verify Memory Lightning name appears
+    const memoryLightningName = page.locator('text=🧠 Memory Lightning')
+    await expect(memoryLightningName).toBeVisible()
+
+    // Navigate back to games page
+    await page.click('a[href="/games"]')
+    await page.waitForURL('/games')
+
+    // Game name should disappear
+    await expect(memoryLightningName).not.toBeVisible()
+  })
+
+  test('should show correct game name when switching between different games', async ({ page }) => {
+    // Override baseURL for this test to match running dev server
+    const baseURL = 'http://localhost:3000'
+
+    // Start at Memory Pairs
+    await page.goto(`${baseURL}/games/matching`)
+    await expect(page.locator('text=🧩 Memory Pairs')).toBeVisible()
+
+    // Switch to Memory Lightning
+    await page.click('a[href="/games/memory-quiz"]')
+    await page.waitForURL('/games/memory-quiz')
+
+    // Should show Memory Lightning and NOT Memory Pairs
+    await expect(page.locator('text=🧠 Memory Lightning')).toBeVisible()
+    await expect(page.locator('text=🧩 Memory Pairs')).not.toBeVisible()
+
+    // Switch back to Memory Pairs
+    await page.click('a[href="/games/matching"]')
+    await page.waitForURL('/games/matching')
+
+    // Should show Memory Pairs and NOT Memory Lightning
+    await expect(page.locator('text=🧩 Memory Pairs')).toBeVisible()
+    await expect(page.locator('text=🧠 Memory Lightning')).not.toBeVisible()
+  })
+
+  test('should not persist game name when navigating through intermediate pages', async ({ page }) => {
+    // Override baseURL for this test to match running dev server
+    const baseURL = 'http://localhost:3000'
+
+    // Start at Memory Pairs game - should show game name
+    await page.goto(`${baseURL}/games/matching`)
+    const memoryPairsName = page.locator('text=🧩 Memory Pairs')
+    await expect(memoryPairsName).toBeVisible()
+
+    // Navigate to Guide page - game name should disappear
+    await page.click('a[href="/guide"]')
+    await page.waitForURL('/guide')
+    await expect(memoryPairsName).not.toBeVisible()
+
+    // Navigate to Games page - game name should still be gone
+    await page.click('a[href="/games"]')
+    await page.waitForURL('/games')
+    await expect(memoryPairsName).not.toBeVisible()
+
+    // Test another path: Game -> Create -> Games
+    await page.goto(`${baseURL}/games/memory-quiz`)
+    const memoryLightningName = page.locator('text=🧠 Memory Lightning')
+    await expect(memoryLightningName).toBeVisible()
+
+    // Navigate to Create page
+    await page.click('a[href="/create"]')
+    await page.waitForURL('/create')
+    await expect(memoryLightningName).not.toBeVisible()
+
+    // Navigate to Games page - should not show any game name
+    await page.click('a[href="/games"]')
+    await page.waitForURL('/games')
+    await expect(memoryLightningName).not.toBeVisible()
+    await expect(memoryPairsName).not.toBeVisible()
+  })
+})

apps/web/src/app/@nav/create/page.tsx

@@ -0,0 +1,3 @@
+export default function CreateNav() {
+  return null
+}

apps/web/src/app/@nav/games/page.tsx

@@ -0,0 +1,3 @@
+export default function GamesNav() {
+  return null
+}

apps/web/src/app/@nav/guide/page.tsx

@@ -0,0 +1,3 @@
+export default function GuideNav() {
+  return null
+}

apps/web/src/app/@nav/page.tsx

@@ -0,0 +1,3 @@
+export default function HomeNav() {
+  return null
+}