Early returns in ValidateOrder

No else after return

Switch for Status validation

Named booleans in CanProcess

Business-meaningful boolean names

Initialized Items and Metadata

strings.Builder in ExportToCSV

No += in loop

strconv for ID conversion

%q in error messages

Capacity hint for ExportToCSV

Default-then-override pattern

context.Context first

Options struct used

Named fields in ServiceConfig literal

Named fields in all struct literals

Multi-line 4+ argument call

Closing paren on own line

No line over ~140 chars

Initialized Metadata field

var for zero-value fields

Service constant extracted

context.Context not in options struct

Logger not a standalone param

Generics not interface{}

Filter capacity hint

Map capacity hint

GroupBy map initialized

range for iteration

strings.Builder in Render

No += in Render loop

Internal helpers unexported

No blank imports

No dot imports

Pointer for Report mutation

NewReport returns initialized slice