Emit catalog events from workflow code - #105

Most of order's catalog events are decided in workflow code: the saga's
failed/compensated outcome, each compensation step, a completion or
inventory commit that exhausted its retries. Only the SDK's
replay-aware logger may run there, and the facade may not.

temporalx.WorkflowEvent writes through workflow.GetLogger, so a
replayed history writes nothing; a live run writes the event once, and
the replay test proves the code ran. It applies the facade's grammar:
an invalid name goes under event.invalid and a caller's own event
attribute is renamed.

An invalid event name is now cut the way the facade cuts it: invalid
UTF-8 repaired, the cut on a rune boundary, and a truncation marker, so
event.invalid reads the same on both paths. The SDK logger skips one
more frame, so the record's source is the workflow line that called
WorkflowEvent rather than temporalx. The doc states when replay safety
holds and how non-standard levels map; the grammar tests pin exact
values, including the 64-byte edge and a cut inside a rune.