Load QuickBooks Chart of Accounts

Fetch and store the complete chart of accounts from QuickBooks Online for mapping configuration.

Note: - Use QuickBooks Query API to fetch all Account objects - Store accounts with: ID, name, type, account number, parent account (if sub-account) - Support hierarchical account structure (parent/sub-account relationships) - Filter to active accounts only (exclude inactive) - Account types include: Bank, Other Current Asset, Fixed Asset, Other Asset, Accounts Payable, Credit Card, Other Current Liability, Long Term Liability, Equity, Income, Cost of Goods Sold, Expense, Other Income, Other Expense - Handle pagination if customer has >1000 accounts - Provide "Refresh Accounts" action in configuration UI - Reference PoC account loading implementation

Open questions: - Should we store account history or always fetch fresh from QuickBooks?