fix(#73): consume canonical Weekend Context contract and repair navigation

Address the independent review blockers on PR #80 after rebasing onto the
authoritative #72 Weekend Context API.

- Replace the invented frontend WeekendContext with the exact backend contract
  (temporal_state, previous/focus/next meetings, previous_completed/active/next/
  default_analysis sessions with availability). Every valid canonical payload now
  maps to a designed state via a total resolveViewState; a well-formed response
  can never fall through to the limited-data placeholder.
- Make the canonical read the single source of truth: useWeekendContext no longer
  fans out to season/meetings/per-weekend/OpenF1/live queries. Only supplementary
  championship + news reads run, and only once the canonical context resolves.
- Fix the Prepare/analysis flow: /preview is a stable alias that renders the
  preparation surface (PreSessionView) instead of redirecting back to the same
  between-races screen.
- One primary navigation system per breakpoint: the mobile top-bar links are
  hidden so the bottom bar is the sole primary nav, and Admin is moved out of
  every Primary landmark into an operator-utilities toolbar.
- Add Vitest coverage for the contract mapping, every temporal state, loading/
  error/limited surfaces, the no-fanout guarantee, the /preview CTA, and the nav
  hierarchy; add hermetic Playwright journeys (seeded + injected canonical
  payloads), 390/768/1440 overflow checks, and Weekend visual snapshots. Retire
  the stale Command Center specs/snapshots.

Co-authored-by: Cursor <cursoragent@cursor.com>

tests/weekend.spec.ts

@@ -0,0 +1,118 @@
+import { test, expect, type Page } from '@playwright/test'
+
+const FULL_SESSION = 9472
+
+async function documentOverflow(page: Page): Promise<number> {
+  return page.evaluate(() => {
+    const doc = document.documentElement
+    return doc.scrollWidth - doc.clientWidth
+  })
+}
+
+test.describe('Weekend home (seeded canonical context)', () => {
+  test('renders the Weekend home from the canonical endpoint, not the limited fallback', async ({ page }) => {
+    await page.goto('/')
+
+    await expect(page.getByTestId('weekend-page')).toBeVisible()
+    // The seeded DB (Monaco 2025, completed) resolves to season_complete, driven
+    // by the canonical /api/v1/weekend-context endpoint.
+    await expect(page.getByTestId('weekend-page')).toHaveAttribute('data-temporal-state', 'season_complete')
+    await expect(page.getByTestId('weekend-between-races')).toBeVisible()
+    await expect(page.getByTestId('weekend-limited')).toHaveCount(0)
+    // No ingest/dataset terminology on the Weekend surface.
+    await expect(page.getByText(/ingest/i)).toHaveCount(0)
+  })
+
+  test('the completed-event CTA opens the canonical analysis session in Race Hub', async ({ page }) => {
+    await page.goto('/')
+    await expect(page.getByTestId('wk-last-event')).toBeVisible()
+    await page.getByTestId('wk-explore-race-story').click()
+    await expect(page).toHaveURL(/\/race-hub\?session_key=\d+/)
+    await expect(page.getByTestId('race-hub')).toBeVisible()
+  })
+
+  test('/preview alias resolves without looping back to the same screen', async ({ page }) => {
+    await page.goto('/preview')
+    // In the seeded season-complete state there is no next event, so /preview
+    // resolves to the Weekend home rather than a redirect loop.
+    await expect(page.getByTestId('weekend-page')).toBeVisible()
+    await expect(page).toHaveURL(/\/preview$/)
+  })
+
+  test('existing deep-link routes remain valid', async ({ page }) => {
+    await page.goto(`/race-hub?session_key=${FULL_SESSION}`)
+    await expect(page.getByTestId('race-hub')).toBeVisible()
+    await expect(page.getByTestId('rh-overview')).toBeVisible()
+
+    await page.goto('/admin')
+    await expect(page.getByTestId('data-library')).toBeVisible()
+
+    await page.goto('/live')
+    await expect(page.getByTestId('live-empty')).toBeVisible()
+
+    await page.goto('/explore')
+    await expect(page.getByTestId('explore-page')).toBeVisible()
+  })
+})
+
+test.describe('Weekend navigation hierarchy', () => {
+  test('all four destinations are reachable from primary navigation', async ({ page }) => {
+    await page.goto('/')
+    const primary = page.getByRole('navigation', { name: 'Primary' }).first()
+    for (const [label, url] of [
+      ['Championship', /\/championship/],
+      ['Briefing', /\/briefing/],
+      ['Explore', /\/explore/],
+      ['Weekend', /\/$/],
+    ] as const) {
+      await primary.getByRole('link', { name: label, exact: true }).click()
+      await expect(page).toHaveURL(url)
+    }
+  })
+
+  test('Admin is an operator utility outside the Primary landmark', async ({ page }) => {
+    await page.goto('/')
+    const primaries = page.getByRole('navigation', { name: 'Primary' })
+    await expect(primaries.first()).toBeVisible()
+    // Admin must not appear inside any Primary landmark.
+    await expect(primaries.getByRole('link', { name: /Admin/i })).toHaveCount(0)
+    await expect(
+      page.getByRole('toolbar', { name: 'Operator utilities' }).getByRole('link', { name: 'Admin' }),
+    ).toBeVisible()
+  })
+})
+
+test.describe('Weekend responsive — no global horizontal overflow', () => {
+  for (const { name, width, height } of [
+    { name: 'mobile 390', width: 390, height: 844 },
+    { name: 'tablet 768', width: 768, height: 1024 },
+    { name: 'desktop 1440', width: 1440, height: 900 },
+  ]) {
+    test(`no document overflow at ${name}`, async ({ page }) => {
+      await page.setViewportSize({ width, height })
+      await page.goto('/')
+      await expect(page.getByTestId('weekend-between-races')).toBeVisible()
+      expect(await documentOverflow(page)).toBeLessThanOrEqual(1)
+    })
+  }
+
+  test('mobile shows exactly one visible primary navigation (bottom bar)', async ({ page }) => {
+    await page.setViewportSize({ width: 390, height: 844 })
+    await page.goto('/')
+    await expect(page.getByTestId('weekend-page')).toBeVisible()
+
+    // The bottom bar is the single visible primary nav; the top bar's links are
+    // hidden by CSS at this breakpoint.
+    const bottom = page.locator('.app-bottom-nav')
+    await expect(bottom).toBeVisible()
+    await expect(bottom.getByRole('link')).toHaveCount(4)
+
+    const topLinks = page.locator('.app-nav .nav-links')
+    await expect(topLinks).toBeHidden()
+
+    // All four destinations remain reachable via the bottom bar.
+    for (const label of ['Weekend', 'Championship', 'Briefing', 'Explore']) {
+      await expect(bottom.getByRole('link', { name: new RegExp(label) })).toBeVisible()
+    }
+  })
+})