feat(properties): expenses tab with electricity+water chart

- expense_kind enum (utilities + maintenance/repair/cleaning/insurance/tax/rent/other)
- property_expenses table with optional link to a property_accounts row
  (preserves history via ON DELETE SET NULL)
- services/expenses.ts: CRUD + 12-month monthly series aggregation +
  year-to-date summary by kind
- /properties/[id]/expenses tab: inline SVG line chart for electricity +
  water last 12 months (no chart library), summary card, add/edit/delete
  inline with account linking when kind matches

src/lib/server/db/schema/index.ts

@@ -3,6 +3,7 @@ export * from './tenancy';
 export * from './properties';
 export * from './rooms';
 export * from './accounts';
+export * from './expenses';
 export * from './assets';
 export * from './documents';
 export * from './checklists';