fix: resolve TypeScript strict mode errors

src/app/dashboard-client.tsx

@@ -422,7 +422,7 @@ function buildDailySpendData(breakdown: SpendBreakdownRow[]): {
     const point = byDate.get(row.date) as Record<string, number>;
     const firstName = row.name.split(" ")[0] ?? row.name;
     const dollars = row.spend_cents / 100;
-    point.total += dollars;
+    point.total = (point.total ?? 0) + dollars;
     if (topNames.includes(firstName)) {
       point[firstName] = (point[firstName] as number) + dollars;
     } else {

src/app/insights/insights-client.tsx

@@ -150,7 +150,7 @@ export function InsightsClient({ data }: { data: InsightsData }) {
       if (!byDate.has(entry.date)) byDate.set(entry.date, { _total: 0 });
       const row = byDate.get(entry.date) as Record<string, number>;
       row[model] = (row[model] ?? 0) + entry.messages;
-      row._total += entry.messages;
+      row._total = (row._total ?? 0) + entry.messages;
     }
     const result: Array<Record<string, string | number>> = [];
     for (const [date, row] of [...byDate.entries()].sort((a, b) => a[0].localeCompare(b[0]))) {
@@ -658,7 +658,7 @@ function ModelEfficiencySection({ data }: { data: ModelEfficiencyEntry[] }) {
                     <LabelList
                       dataKey="precision_pct"
                       position="right"
-                      formatter={(v: number) => `${v}%`}
+                      formatter={(v) => `${v ?? ""}%`}
                       style={{ fontSize: 10, fill: "#a1a1aa", fontFamily: "monospace" }}
                     />
                   </Bar>

src/components/dashboard/members-table.tsx

@@ -21,7 +21,7 @@ function rankBadge(rank: number) {
   return `#${rank}`;
 }
 
-function SortIcon({ active, asc }: { active: boolean; asc: boolean }) {
+function SortIcon({ active, asc }: { col?: string; active: boolean; asc: boolean }) {
   if (!active) return <span className="text-zinc-700 ml-0.5">↕</span>;
   return <span className="text-blue-400 ml-0.5">{asc ? "↑" : "↓"}</span>;
 }