feat: enhance schedule slot handling with episode details and duration calculation

k-tv-frontend/app/(main)/tv/components/schedule-overlay.tsx

@@ -3,7 +3,12 @@ import { cn } from "@/lib/utils";
 
 export interface ScheduleSlot {
   id: string;
+  /** Headline: series name for episodes, film title for everything else. */
   title: string;
+  /** Secondary line: "S1 · E3 · Episode Title" for episodes, year for movies. */
+  subtitle?: string | null;
+  /** Rounded slot duration in minutes. */
+  durationMins: number;
   startTime: string; // "HH:MM"
   endTime: string;   // "HH:MM"
   isCurrent?: boolean;
@@ -50,8 +55,17 @@ export function ScheduleOverlay({ channelName, slots }: ScheduleOverlayProps) {
               >
                 {slot.title}
               </p>
+              {slot.subtitle && (
+                <p className={cn(
+                  "truncate text-xs leading-snug",
+                  slot.isCurrent ? "text-zinc-400" : "text-zinc-600"
+                )}>
+                  {slot.subtitle}
+                </p>
+              )}
               <p className="mt-0.5 font-mono text-[10px] text-zinc-600">
                 {slot.startTime} – {slot.endTime}
+                {" · "}{slot.durationMins}m
               </p>
             </div>
           </li>