Rebuilt payment_history.php with 4 summary cards (Total Paid, Outstanding, Invoice Payments, Transactions), dual tables (billing invoice payments with PDF download   transaction log with type/status). Enhanced getPaymentHistory controller to return combined transactions   billing invoices   stats. Added formatDate and truncate JS helpers. Added error handling to all tab loaders (overview, invoices, subscription, usage, payment_history) — spinners now hide on failure with warning messages instead of infinite loading.