Room page: taps stay visible, swatches match, an unreachable blind says so

- A tapped light or blind state now holds for 4s against polled state: a poll
  that starts just after the tap can still return the device's old state
  (a Hue light reports about a second after HA answers), which flipped the
  card back and looked like the tap had failed.
- Swatches match what a light reports, not only what it was sent: a Hue
  light hands rgb_color back at full intensity, so the exact comparison never
  showed a swatch as selected.
- The Rollo card says "Nicht erreichbar" and disables its buttons while HA has
  the cover as unavailable, instead of showing "Offen"; up/down show the
  blind as moving at once, so they are not pressed again and again.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

web/src/hooks/useHomeAssistant.ts

@@ -12,6 +12,12 @@ import type { HaConfig, HaEntityState } from "../api/types";
 
 const POLL_INTERVAL_MS = 2500;
 
+/** How long a tap's optimistic state wins over polled state. A device reports back
+ * after HA has already answered the service call - a Hue light about a second later -
+ * so a poll that *starts* just after the tap can still return the old colour and flip
+ * the card back, which reads as "the tap did not work". */
+const OPTIMISTIC_HOLD_MS = 4000;
+
 export interface HomeAssistant {
   states: Record<string, HaEntityState>;
   loading: boolean;
@@ -52,9 +58,10 @@ export function useHomeAssistant(config: HaConfig | null): HomeAssistant {
       setStates((previous) => {
         const next = { ...previous };
         for (const [entityId, state] of Object.entries(fresh)) {
-          // Only apply this result if no optimistic patch landed after the request
-          // for it went out - otherwise it's stale and would undo a newer change.
-          if (startedAt >= (optimisticAt.current[entityId] ?? 0)) {
+          // Only apply this result if it went out well after the last optimistic
+          // patch - otherwise it may predate the device catching up and would undo a
+          // newer change. See OPTIMISTIC_HOLD_MS.
+          if (startedAt >= (optimisticAt.current[entityId] ?? -Infinity) + OPTIMISTIC_HOLD_MS) {
             next[entityId] = state;
           }
         }