favicon and some TODOs

src/store.ts

@@ -46,7 +46,21 @@ export class Store {
     this.update({ extraExcludedDays: Math.max(0, Math.floor(count) || 0) });
   }
 
+  setActualMealBlocks(value: number | null): void {
+    this.update({ actualMealBlocks: normalizeBalance(value) });
+  }
+
+  setActualFlexDollars(value: number | null): void {
+    this.update({ actualFlexDollars: normalizeBalance(value) });
+  }
+
   private emit(): void {
     for (const l of this.listeners) l();
   }
 }
+
+/** Clamp an entered balance to a non-negative number, or null if blank/invalid. */
+function normalizeBalance(value: number | null): number | null {
+  if (value === null || !Number.isFinite(value)) return null;
+  return Math.max(0, value);
+}