router: update all Route callers for NormalizedInput + add invariant tests (slice 11)

Migrate 54 test call sites to construct NormalizedInput{Text: ...}.
Add invariant tests:
- TestNormalizedInputReachesRouteIntact: ingress NormalizedInput reaches Route
- TestTryFastPathReceivesMatchText: TryFastPath gets the same input
- TestMatchTextDoesNotChangeRouting: same Text + different MatchText → same Decision
- TestDecisionUtteranceEqualsInputText: Decision.Utterance == input.Text

internal/router/eval/claims_test.go

@@ -123,7 +123,7 @@ func reportConfidences(t *testing.T, name string, emb router.Embedder) {
 	byMargin := map[string]*bucket{}
 	var cosines, margins []float64
 	for _, c := range f.Cases {
-		d, err := r.Route(context.Background(), c.Utterance, now)
+		d, err := r.Route(context.Background(), router.NormalizedInput{Text: c.Utterance}, now)
 		if err != nil {
 			t.Fatalf("%s: %v", c.ID, err)
 		}

internal/router/eval/resolution_test.go

@@ -78,7 +78,7 @@ func TestResolutionMethodMatrix(t *testing.T) {
 		resolved := 0
 	 counts := [5]int{} // fixed, matcher, raw, llm, fallback
 		for _, c := range rf.Cases {
-			d, err := r.Route(ctx, c.Utterance, rfNow)
+			d, err := r.Route(ctx, router.NormalizedInput{Text: c.Utterance}, rfNow)
 			if err != nil || d.Intent != router.IntentAct {
 				continue
 			}
@@ -132,7 +132,7 @@ func TestResolutionMethodMatrix(t *testing.T) {
 		resolved := 0
 		counts := [5]int{}
 		for _, c := range ef.Cases {
-			d, err := r2.Route(ctx, c.Utterance, efNow)
+			d, err := r2.Route(ctx, router.NormalizedInput{Text: c.Utterance}, efNow)
 			if err != nil || d.Intent != router.IntentAct {
 				continue
 			}
@@ -189,7 +189,7 @@ func TestShadowMatcherComparison(t *testing.T) {
 
 	same, different, routeOnly, matcherOnly, missBoth, total := 0, 0, 0, 0, 0, 0
 	for _, c := range f.Cases {
-		d, err := r.Route(ctx, c.Utterance, now)
+		d, err := r.Route(ctx, router.NormalizedInput{Text: c.Utterance}, now)
 		if err != nil || d.Intent != router.IntentAct {
 			continue
 		}