refactor: remove all any types, add strict GraphQL scalar typing

- Add strictScalars: true to codegen.ts with proper scalar mappings
  (Date, Decimal, JSONString, JSON, UUID, BigInt → string/Record)
- Replace all ref<any[]> with proper GraphQL-derived types
- Add type guards for null filtering in arrays
- Fix bugs exposed by typing (locationLatitude vs latitude, etc.)
- Add interfaces for external components (MapboxSearchBox)

This enables end-to-end type safety from GraphQL schema to frontend.

app/pages/clientarea/billing/index.vue

@@ -95,6 +95,10 @@
 </template>
 
 <script setup lang="ts">
+import type { GetTeamTransactionsQueryResult } from '~/composables/graphql/team/billing-generated'
+
+type Transaction = NonNullable<NonNullable<GetTeamTransactionsQueryResult['teamTransactions']>[number]>
+
 definePageMeta({
   layout: 'topnav',
   middleware: ['auth-oidc']
@@ -112,7 +116,7 @@ const balance = ref({
   exists: false
 })
 
-const transactions = ref<any[]>([])
+const transactions = ref<Transaction[]>([])
 
 const formatCurrency = (amount: number) => {
   // Amount is in kopecks, convert to base units
@@ -130,7 +134,7 @@ const formatAmount = (amount: number) => {
   }).format(amount / 100)
 }
 
-const formatTimestamp = (timestamp: number) => {
+const formatTimestamp = (timestamp: number | null | undefined) => {
   if (!timestamp) return '—'
   // TigerBeetle timestamp is in nanoseconds since epoch
   const date = new Date(timestamp / 1000000)
@@ -157,8 +161,8 @@ const loadBalance = async () => {
     if (data.value?.teamBalance) {
       balance.value = data.value.teamBalance
     }
-  } catch (e: any) {
-    error.value = e.message || t('billing.errors.load_failed')
+  } catch (e: unknown) {
+    error.value = e instanceof Error ? e.message : t('billing.errors.load_failed')
   } finally {
     isLoading.value = false
   }
@@ -171,7 +175,7 @@ const loadTransactions = async () => {
 
     if (txError.value) throw txError.value
 
-    transactions.value = data.value?.teamTransactions || []
+    transactions.value = (data.value?.teamTransactions || []).filter((tx): tx is Transaction => tx !== null)
   } catch (e) {
     console.error('Failed to load transactions', e)
   }