Clean up documentation consistency

internal/normalizers/common/finalize.go

@@ -9,12 +9,12 @@ import (
 )
 
 // Finalize builds the output event envelope by copying the input and applying the
-// canonical schema/payload, plus (optionally) EffectiveAt.
+// canonical schema/payload, plus an optional effective time.
 //
 // Important behavior:
 //   - ID/Kind/Source/EmittedAt are preserved by copying the input event.
-//   - EffectiveAt is only overwritten when effectiveAt is non-zero.
-//     If effectiveAt is zero, any existing in.EffectiveAt is preserved.
+//   - EffectiveAt is only overwritten when the supplied effective time is non-zero.
+//     If the supplied time is zero, any existing in.EffectiveAt is preserved.
 //   - Payload floats are rounded to a stable wire-friendly precision (see round.go).
 func Finalize(in event.Event, outSchema string, outPayload any, effectiveAt time.Time) (*event.Event, error) {
 	// Enforce stable numeric presentation for weather payloads before delegating to feedkit's