feat: replace hardcoded package assumptions with profile abstraction (#379)

backend/src/utils/package-profiles.ts

@@ -0,0 +1,32 @@
+export const PACKAGE_TYPES = ["blister", "bottle", "tube", "liquid_container"] as const;
+
+export type PackageType = (typeof PACKAGE_TYPES)[number];
+
+const PACKAGE_TYPE_SET = new Set<string>(PACKAGE_TYPES);
+
+export function normalizePackageType(packageType?: string | null): PackageType {
+	if (packageType && PACKAGE_TYPE_SET.has(packageType)) {
+		return packageType as PackageType;
+	}
+	return "blister";
+}
+
+export function isTubePackageType(packageType?: string | null): boolean {
+	return normalizePackageType(packageType) === "tube";
+}
+
+export function isLiquidContainerPackageType(packageType?: string | null): boolean {
+	return normalizePackageType(packageType) === "liquid_container";
+}
+
+export function isAmountBasedPackageType(packageType?: string | null): boolean {
+	const normalized = normalizePackageType(packageType);
+	return normalized === "bottle" || normalized === "tube" || normalized === "liquid_container";
+}
+
+export function getPlannerUnitKind(packageType?: string | null): "pills" | "ml" | "units" {
+	const normalized = normalizePackageType(packageType);
+	if (normalized === "tube") return "units";
+	if (normalized === "liquid_container") return "ml";
+	return "pills";
+}