polish: mobile view layout and usability improvements

Header:
- Hide "X of Y parks open this week" badge on mobile (hidden sm:inline-flex)
  — title + Coaster Mode button fit cleanly on a 390px screen

WeekNav:
- Arrow button padding 6px 14px → 10px 16px, minWidth: 44px for proper
  touch targets (Apple HIG recommends 44px minimum)
- Date label minWidth 200px → 140px, prevents crowding on small screens

ParkCard:
- Name container: flex: 1, minWidth: 0 so long park names don't push
  the status badge off-screen; name wraps naturally instead of overflowing
- Timezone abbreviation: opacity: 0.6 → color: var(--color-text-dim),
  semantic dimming instead of opacity for better accessibility
- Passholder label: 0.58rem → 0.65rem (was below WCAG minimum)

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

components/ParkCard.tsx

@@ -40,7 +40,7 @@ export function ParkCard({ park, weekDates, parkData, today, openRideCount, coas
           justifyContent: "space-between",
           gap: 12,
         }}>
-          <div>
+          <div style={{ flex: 1, minWidth: 0 }}>
             <div style={{
               fontSize: "0.95rem",
               fontWeight: 600,
@@ -137,10 +137,10 @@ export function ParkCard({ park, weekDates, parkData, today, openRideCount, coas
                   <div style={{ display: "flex", alignItems: "center", gap: 8 }}>
                     {isPH && (
                       <span style={{
-                        fontSize: "0.58rem",
+                        fontSize: "0.65rem",
                         fontWeight: 700,
                         color: "var(--color-ph-label)",
-                        letterSpacing: "0.05em",
+                        letterSpacing: "0.04em",
                         textTransform: "uppercase",
                       }}>
                         Passholder
@@ -156,7 +156,7 @@ export function ParkCard({ park, weekDates, parkData, today, openRideCount, coas
                         : "var(--color-open-hours)",
                     }}>
                       {dayData.hoursLabel}{" "}
-                      <span style={{ fontSize: "0.68rem", fontWeight: 400, opacity: 0.6 }}>
+                      <span style={{ fontSize: "0.68rem", fontWeight: 400, color: "var(--color-text-dim)" }}>
                         {tzAbbr}
                       </span>
                     </span>