Use a pinia store to manage account state

Refactor the existing scattered code dealing with the account state into
a pinia store.

stores/account.ts

@@ -0,0 +1,60 @@
+import type { Account } from "~/shared/types/account";
+
+export const useAccountStore = defineStore("account", () => {
+	const runtimeConfig = useRuntimeConfig();
+	const sessionStore = useSessionStore();
+	const state = {
+		valid: ref<boolean>(false),
+		id: ref<number>(),
+		name: ref<string>(),
+		timezone: ref<string>(),
+		type: ref<Account["type"]>(),
+		interestedIds: ref<Set<string>>(),
+	};
+
+	watchEffect(() => {
+		const account = sessionStore.account;
+		state.valid.value = Boolean(account);
+		state.id.value = account?.id;
+		state.name.value = account?.name;
+		state.timezone.value = account?.timezone;
+		state.type.value = account?.type;
+		state.interestedIds.value = account?.interestedIds ? new Set(account.interestedIds) : undefined;
+	});
+
+	const getters = {
+		isCrew: computed(() => state.type.value === "crew" || state.type.value === "admin"),
+		canEdit: computed(() => state.type.value === "admin" || state.type.value === "crew" ),
+		canEditPublic: computed(() => state.type.value === "admin"),
+		activeTimezone: computed(() => state.timezone.value || runtimeConfig.public.defaultTimezone),
+		defaultTimezone: computed(() => runtimeConfig.public.defaultTimezone),
+	};
+
+	const actions = {
+		async toggleInterestedId(id: string, slotIds?: string[]) {
+			if (!state.interestedIds.value) {
+				throw Error("accountStore.toggleInterestedId: Invalid state")
+			}
+			let newIds = [...state.interestedIds.value ?? []];
+			if (state.interestedIds.value.has(id)) {
+				newIds = newIds.filter(newId => newId !== id);
+			} else {
+				newIds.push(id);
+				if (slotIds) {
+					const filterIds = new Set(slotIds);
+					newIds = newIds.filter(newId => !filterIds.has(newId));
+				}
+			}
+			await $fetch("/api/account", {
+				method: "PATCH",
+				body: { interestedIds: newIds },
+			})
+			await sessionStore.fetch();
+		},
+	};
+	return {
+		...state,
+		...getters,
+		...actions,
+	};
+});