Fix MoodBarChart to show all 5 mood categories

Removed filter that hid moods with zero count, ensuring all mood
options display even when user hasn't logged that mood in the period.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Shared/Views/MonthView/MonthView.swift

@@ -427,7 +427,7 @@ struct MoodBarChart: View {
 
     var body: some View {
         VStack(spacing: 8) {
-            ForEach(metrics.filter { $0.total > 0 }) { metric in
+            ForEach(metrics) { metric in
                 HStack(spacing: 10) {
                     // Mood icon
                     imagePack.icon(forMood: metric.mood)