Fix manual switch reverting instantly, add weather forecast

- scheduler: "Show X now" was a true one-shot -- reverted on the very next
  5s tick, causing the flash-to-X-then-flash-back-to-clock behavior. Now
  pins for 5 minutes (still preemptable by Navidrome priority, which stays
  authoritative). Added a "Resume automatic" action/button and status
  display showing what's pinned and until when.
- weather: daily forecast strip (3/5/7 days, selectable in settings) below
  current conditions, via Open-Meteo's daily= params in the same request.
  Fixed a bad symbol choice along the way -- DejaVu Sans has no glyph for
  the partly-cloudy emoji, was rendering as a tofu box; swapped to the
  plain cloud symbol, verified glyph coverage for the whole WMO code table.

web/templates/base.html

@@ -108,7 +108,7 @@
     label { display: block; font-weight: 600; margin-bottom: 0.35rem; font-size: 0.85rem; }
     .hint { font-size: 0.78rem; color: var(--text-muted); margin: 0.35rem 0 0; }
 
-    input[type=text], input[type=password], input[type=number] {
+    input[type=text], input[type=password], input[type=number], select, input[type=file] {
       width: 100%;
       padding: 0.6rem 0.7rem;
       font-size: 0.95rem;