Bigger tip chip(s), soft umbrella tier, and a jacket tip

- Umbrella tip now bigger (larger padding/font/icon) and there can be
  more than one chip shown at once (e.g. cold + rainy).
- Added a softer 'You might want an umbrella' tier: shown when the
  existing strong threshold isn't met but any remaining hour today
  still has a real (>10%) rain chance -- previously that case showed
  nothing at all.
- Added a jacket tip: shown when today's forecast high is below 12°C.
  Both new thresholds are named constants at the top of summary.js,
  easy to retune without touching the logic.

summary.js's umbrella boolean is replaced by a tips[] array so future
nudges (e.g. a UV/sun-cream tip, if we add UV index data) slot in the
same way without another one-off boolean + span.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

backend/src/lib/summary.js

@@ -10,6 +10,11 @@
 const RAIN_ICONS = new Set(['drizzle', 'rain-light', 'rain-heavy', 'sleet', 'hail'])
 const SNOW_ICONS = new Set(['snow-light', 'snow-heavy'])
 
+// Tunable thresholds for the "now" panel's tip chips — all easy to adjust here
+// without touching the logic that uses them.
+const UMBRELLA_SOFT_PRECIP_PCT = 10  // any remaining hour above this -> "might want"
+const JACKET_HIGH_TEMP_C = 12        // today's forecast high below this -> jacket tip
+
 // summarizeToday(points, nowHour) — `points` is today's hourly forecast_points rows
 // (already icon-normalized), `nowHour` is 0-23 in Europe/London. Returns null if
 // there's nothing to summarize (no data yet).
@@ -73,16 +78,37 @@ export function summarizeToday(points, nowHour) {
     ? 'Thunderstorms possible'
     : null
 
-  // Umbrella nudge: real rain chance either right now or coming up later today.
-  const umbrella = laterWetFraction > 0.25 || rainFraction > 0.25
+  // Tip chips — small, actionable nudges under the headline. Each is
+  // independent (a cold rainy day can show both), ordered by how likely
+  // reception actually wants a guest to see it.
+  const tips = []
+
+  // Umbrella: the existing "real rain chance" threshold gets the strong
+  // wording; falling short of that but with a real (if lesser) chance
+  // still on the cards for later today gets a softer nudge instead of
+  // nothing at all.
+  const umbrellaStrong = laterWetFraction > 0.25 || rainFraction > 0.25
+  const umbrellaSoft = !umbrellaStrong &&
+    laterPoints.some(p => p.precip_prob != null && p.precip_prob > UMBRELLA_SOFT_PRECIP_PCT)
+  if (umbrellaStrong) {
+    tips.push({ key: 'umbrella', text: "Don't forget your umbrella" })
+  } else if (umbrellaSoft) {
+    tips.push({ key: 'umbrella-soft', text: 'You might want an umbrella' })
+  }
+
+  // Jacket: keyed off today's forecast high, not "right now" -- same framing
+  // as the big temp above it.
+  if (highPoint.temp_c < JACKET_HIGH_TEMP_C) {
+    tips.push({ key: 'jacket', text: "Don't forget your jacket" })
+  }
 
   return {
     headline,
     note,
-    umbrella,
     highTemp: highPoint.temp_c,
     highFeelsLike: highPoint.feels_like_c,
     rainChance: rainPeakPoint ? { prob: rainPeakPoint.precip_prob, ts: rainPeakPoint.ts } : null,
+    tips,
   }
 }