Align validator identity and span domain checks

internal/framework/proposals/proposal.go

@@ -2,7 +2,6 @@ package proposals
 
 import (
 	"fmt"
-	"strings"
 )
 
 // CorrectionProposal is the base proposal emitted by correction modules.
@@ -35,7 +34,7 @@ func (p CorrectionProposal) Validate() error {
 	if p.TargetSegmentID <= 0 {
 		return fmt.Errorf("proposal id must be positive")
 	}
-	if strings.TrimSpace(p.OriginalText) == "" {
+	if p.OriginalText == "" {
 		return fmt.Errorf("proposal original_text must not be empty")
 	}
 	if p.Confidence < 0.0 || p.Confidence > 1.0 {