fix(home): drop greeting date; fix touch scroll; tokenize TopBar icons

- Removes the date label from the greeting row (user request — тoo dense
  on tablet and redundant with TopBar clock).
- Scrolling: drops overflowY: auto on the inner Events/Notes cards and
  removes flex: 1 / minHeight: 0 from their grid. On iPad-class touch
  nested scroll containers fought the root scroll; now only the root
  scrolls, which the browser handles natively.
- TopBar: replaces hardcoded rgba(255,255,255,X) on sensor icons, chip
  background, chip border and header bottom-border with semantic tokens
  (--text-tertiary, --surface-2, --border-subtle, --hairline) so the
  thermometer/humidity/wind icons are visible in light theme.

components/TopBar.tsx

@@ -44,7 +44,7 @@ export default function TopBar({ sensors, haConnected }: TopBarProps) {
           alignItems: 'center',
           justifyContent: 'space-between',
           padding: '0 24px',
-          borderBottom: '1px solid rgba(255,255,255,0.04)',
+          borderBottom: '1px solid var(--hairline)',
           background: 'transparent',
           flexShrink: 0,
           position: 'relative',
@@ -82,17 +82,17 @@ export default function TopBar({ sensors, haConnected }: TopBarProps) {
             <div style={{
               display: 'flex', alignItems: 'center', gap: 4,
               padding: '8px 14px', borderRadius: 14,
-              background: 'rgba(255,255,255,0.03)', border: '1px solid rgba(255,255,255,0.05)',
+              background: 'var(--surface-2)', border: '1px solid var(--border-subtle)',
             }}>
-              <Thermometer size={14} color="rgba(255,255,255,0.35)" />
+              <Thermometer size={14} color="var(--text-tertiary)" />
               <span style={{ fontSize: 13, fontWeight: 600, color: 'var(--text-primary)', marginRight: 8 }}>
                 {sensors.temperature}°
               </span>
-              <Droplets size={14} color="rgba(255,255,255,0.35)" />
+              <Droplets size={14} color="var(--text-tertiary)" />
               <span style={{ fontSize: 13, fontWeight: 600, color: 'var(--text-primary)', marginRight: 8 }}>
                 {sensors.humidity}%
               </span>
-              <Wind size={14} color="rgba(255,255,255,0.35)" />
+              <Wind size={14} color="var(--text-tertiary)" />
               <span style={{ fontSize: 13, color: 'var(--text-secondary)' }}>
                 {sensors.pm25}
               </span>