Costs, orders, invoices, and credits pages hardened

Several pages that previously showed empty tables or stale data under error conditions now load correctly and surface actionable status messages.

A round of fixes across the commerce pages ensures that partial failures no longer result in silent empty states.

The costs page loads cost data even when customer names cannot be resolved

A notice is shown when the trace list is capped at its maximum size, so you know results may be incomplete

Trace-load failures now display an error message instead of an empty table

Orders, invoices, and credits lists are now wired to their real APIs, replacing the last remaining mock responses on those pages