fix(#75): preserve Race Hub meeting/session on Weekend return

Add an explicit Back to Weekend link that deep-links to /?meeting_key&session_key,
restore that focus on the adaptive Weekend home with a Continue analysis CTA, and
regenerate Race Hub visual baselines against the integrated #80 nav.

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

frontend/src/components/weekend/WeekendFocusBanner.tsx

@@ -0,0 +1,65 @@
+import { Link } from '@tanstack/react-router'
+import { useQuery } from '@tanstack/react-query'
+import { ChevronRight } from 'lucide-react'
+import { fetchWeekend } from '../../api'
+import { meetingIdentity } from '../../lib/weekendContext'
+
+/**
+ * Restores Race Hub → Weekend meeting/session context from the URL search
+ * contract. Deep-linkable and reload-safe — no hidden component memory.
+ */
+export function WeekendFocusBanner({
+  meetingKey,
+  sessionKey,
+}: {
+  meetingKey?: number
+  sessionKey?: number
+}) {
+  const hasFocus = (meetingKey != null && meetingKey > 0) || (sessionKey != null && sessionKey > 0)
+  const weekendQuery = useQuery({
+    queryKey: ['weekend', meetingKey],
+    queryFn: () => fetchWeekend(meetingKey!),
+    enabled: meetingKey != null && meetingKey > 0,
+    staleTime: 60_000,
+  })
+
+  if (!hasFocus) return null
+
+  const weekend = weekendQuery.data
+  const meeting = meetingIdentity(weekend?.meeting)
+  const session = weekend?.sessions.find((s) => s.session.session_key === sessionKey)?.session
+  const meetingLabel = meeting?.meeting_name ?? (meetingKey ? `Meeting ${meetingKey}` : 'Selected weekend')
+  const sessionLabel = session?.session_name ?? (sessionKey ? `Session ${sessionKey}` : null)
+
+  return (
+    <section
+      className="wk-focus"
+      data-testid="wk-focus-context"
+      data-meeting-key={meetingKey ?? undefined}
+      data-session-key={sessionKey ?? undefined}
+      aria-label="Selected weekend context"
+    >
+      <div className="wk-focus-copy">
+        <span className="wk-focus-eyebrow mono">From Race Hub</span>
+        <h2 className="wk-focus-title" data-testid="wk-focus-meeting">
+          {meetingLabel}
+        </h2>
+        {sessionLabel && (
+          <p className="wk-focus-session" data-testid="wk-focus-session">
+            Selected session · {sessionLabel}
+          </p>
+        )}
+      </div>
+      {sessionKey != null && sessionKey > 0 && (
+        <Link
+          to="/race-hub"
+          search={{ session_key: sessionKey }}
+          className="wk-cta wk-cta-primary wk-focus-cta"
+          data-testid="wk-return-analysis"
+        >
+          Continue analysis <ChevronRight size={15} aria-hidden="true" />
+        </Link>
+      )}
+    </section>
+  )
+}