fix(import): add stable .order() to account-sync chart paging (#790, #791 follow-up) (#812)

`syncMappedAccounts` pages the company's full chart via `fetchAllRows` to avoid
the silent 1000-row PostgREST cap, but the query had no `.order()`. Like the
report queries fixed in #811, PostgREST `.range()` paging is only correct with a
stable total order — without it, a chart larger than one page could duplicate or
skip accounts across page boundaries, corrupting the existing-account Map and
causing spurious create/update churn on import.

Order on the unique `account_number` (stable total order; the result is read
into a Map so the order is invisible to callers). Extend the test mock's query
chain to include `.order()`.

Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

lib/import/__tests__/account-sync.test.ts

@@ -46,6 +46,9 @@ function buildCapturingSupabase(opts?: {
       return {
         select: () => ({
           eq: () => ({
+            // Mirrors the stable `.order('account_number')` the sync query now
+            // chains before `.range()` for paging stability.
+            order: () => ({
             range: (from: number, to: number) => ({
               then: (
                 resolve: (v: {
@@ -60,6 +63,7 @@ function buildCapturingSupabase(opts?: {
                 resolve({ data: existing.slice(from, to + 1), error: null })
               },
             }),
+            }),
           }),
         }),
         insert: (rows: Array<Record<string, unknown>>) => {

lib/import/account-sync.ts

@@ -154,6 +154,11 @@ export async function syncMappedAccounts(
           .from('chart_of_accounts')
           .select('account_number, account_name')
           .eq('company_id', companyId)
+          // Stable total order on the unique account_number — paging is only
+          // correct with a deterministic order, else rows duplicate/skip across
+          // pages (see fetch-all.ts ordering invariant). The result is read into
+          // a Map below, so this order is invisible to callers.
+          .order('account_number', { ascending: true })
           .range(from, to)
     )
     existingByNumber = new Map(