fix: dark mode event colors, sidebar height, calendar default, photo badge

- event-config: all bgClass/borderClass get dark:bg-*-950/50 + dark:border-*-800 variants — fixes bright pastel backgrounds in dark mode
- nav: h-screen → h-[100dvh] — fixes sidebar bottom buttons hidden behind mobile browser chrome
- calendar: selectedDay defaults to today, never null — events shown immediately on load
- timeline + dashboard: photo indicator (ImageIcon) on events with metadata.photo

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/app/(app)/dashboard/page.tsx

@@ -9,7 +9,7 @@ import { useBaby } from "@/contexts/baby-context";
 import { checkFeedAlert, getThresholds } from "@/lib/notifications";
 import { format, isToday } from "date-fns";
 import { fr } from "date-fns/locale";
-import { AlertTriangle, Clock, CheckCircle2, Pin, PinOff, Pencil, Check, X, Plus, Trash2, FileText } from "lucide-react";
+import { AlertTriangle, Clock, CheckCircle2, Pin, PinOff, Pencil, Check, X, Plus, Trash2, FileText, ImageIcon } from "lucide-react";
 import { useSession } from "next-auth/react";
 
 const QUICK_LOG_GROUPS: { label: string; types: EventType[] }[] = [
@@ -790,6 +790,9 @@ export default function DashboardPage() {
                       <span className="text-xs text-slate-400 dark:text-slate-500 ml-2">{getEventSummary(ev)}</span>
                     )}
                   </div>
+                  {typeof ev.metadata?.photo === "string" && ev.metadata.photo && (
+                    <ImageIcon className="w-3.5 h-3.5 text-slate-400 dark:text-slate-500 flex-shrink-0" />
+                  )}
                   <span className="text-xs text-slate-400 dark:text-slate-500 flex-shrink-0 font-mono">
                     {format(new Date(ev.startedAt), "HH:mm")}
                   </span>