feat(calendar): future-events accordion, ICS/Google export, multi-day

Right panel now shows all upcoming events as a card-style accordion
(date block + title + location/time chips visible, body collapsed).
Day-grouped with sticky headers + relative countdown.

- ICS download per event (RFC-5545, client-side blob)
- Google Calendar render-template link per event
- Maps link via location field (new schema field)
- Multi-day events via terminEnde (new schema field): grid spans,
  range "Mai / 14–16 / 2026" date block, expanded eventsByDay map
- Tag filter chips (new schema field) above calendar
- Past events <details> at list end, expanded if no future
- Live status badge: "läuft gerade" / "beginnt in 45 min"
  (60s tick interval)
- Today marker on calendar grid (outline + sr-only label)
- Auto-scroll next event into panel viewport on mount
- "Im Kalender anzeigen" jumps grid to event month
- Urgency-colored left border per event: now/today/tomorrow/week/
  later in fire/erde/himmel/stein
- Zebra striping + 4px separator between day-groups
- ARIA: aria-current=date, aria-pressed on day/tag buttons
- Print CSS: details auto-open, day-group break-inside: avoid
- Timezone fix: dayKey uses local Y/M/D not ISO string slice
- Empty-title fallback to "Termin"
- Side-by-side layout from md+ (was always stacked)

Extends CalendarItemData with terminEnde, location, tags
inline until OpenAPI regen catches up.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

src/lib/block-types.ts

@@ -337,9 +337,11 @@ export interface OrganisationsBlockData {
 export interface LiveStrommixBlockData {
   _type?: "live_strommix";
   _slug?: string;
-  /** `full` = card with argument + breakdown disclosure. `compact` = single
-   *  horizontal strip for sidebar / homepage placement. Default: `full`. */
-  variant?: "full" | "compact";
+  /** `full` = card with argument + breakdown disclosure + history accordion.
+   *  `hero` = pct + status + sparkline + trend, no sub-cards or accordion.
+   *  `compact` = single horizontal strip for sidebar / homepage placement.
+   *  Default: `full`. */
+  variant?: "full" | "hero" | "compact";
   intro_headline?: string;
   intro_text?: string;
   threshold_dunkelflaute?: number;
@@ -380,8 +382,17 @@ export interface LiveStrommixBlockData {
   layout?: BlockLayout;
 }
 
-/** Kalender-Item (calendar_item) – aus OpenAPI; terminZeit = ISO date-time. */
-export type CalendarItemData = components["schemas"]["calendar_item"];
+/** Kalender-Item (calendar_item) – aus OpenAPI; terminZeit = ISO date-time.
+ *  Lokale Erweiterungen (terminEnde, location, tags) sind im RustyCMS-Schema
+ *  ergänzt und werden bis zur OpenAPI-Regen hier inline mitgeführt. */
+export type CalendarItemData = components["schemas"]["calendar_item"] & {
+  /** Optionales Endedatum für Mehrtagesveranstaltungen (ISO date-time). */
+  terminEnde?: string;
+  /** Optionale Veranstaltungsort-Beschreibung (Adresse oder Name). */
+  location?: string;
+  /** Optionale Tags zur Filterung. */
+  tags?: string[];
+};
 
 /** Kalender-Block (_type: "calendar"). items nach Resolve: CalendarItemData[]. Basis aus OpenAPI (calendar). */
 export type CalendarBlockData = Omit<