Fix model badge ForEach ID collision and budget warning provider filter

- SessionDetailsList model badges used id: \.name which silently drops
  duplicate model entries. Switched to enumerated offset-based ID.
- Hero budget warning compared against provider-filtered payload instead
  of todayPayload (all providers). Now matches the menubar flame tint.

mac/Sources/CodeBurnMenubar/Views/HeatmapSection.swift

@@ -1086,7 +1086,7 @@ private struct SessionDetailsList: View {
                         .padding(.leading, 4)
                     }
                     HStack(spacing: 4) {
-                        ForEach(sess.models.prefix(3), id: \.name) { model in
+                        ForEach(Array(sess.models.prefix(3).enumerated()), id: \.offset) { _, model in
                             Text(model.name)
                                 .font(.system(size: 8.5, weight: .medium))
                                 .foregroundStyle(.secondary)

mac/Sources/CodeBurnMenubar/Views/HeroSection.swift

@@ -55,7 +55,8 @@ struct HeroSection: View {
 
             if store.selectedPeriod == .today,
                store.dailyBudget > 0,
-               store.payload.current.cost >= store.dailyBudget {
+               let todayCost = store.todayPayload?.current.cost,
+               todayCost >= store.dailyBudget {
                 HStack(spacing: 4) {
                     Image(systemName: "exclamationmark.triangle.fill")
                         .font(.system(size: 10))