router: Router.Route consumes NormalizedInput directly (slice 11)

Change Route from (ctx, utterance string, now) to (ctx, input NormalizedInput, now).
The ingress-constructed NormalizedInput now reaches the cascade intact — no
reconstruction downstream. TryFastPath receives the same input, not a rebuilt one.
All callers (production, eval framework, tests) updated to construct NormalizedInput.

internal/router/eval/llmrouter_test.go

@@ -74,8 +74,8 @@ func TestLLMRouterBaseline(t *testing.T) {
 	// llm-only: the LLM stage in isolation. Route returns (Decision, ok, err);
 	// !ok without an error would be a contract violation, so it is surfaced as
 	// one rather than silently scored as a miss.
-	llmOnly := RouterFunc(func(ctx context.Context, u string, now time.Time) (router.Decision, error) {
-		d, ok, err := lr.Route(ctx, u, now)
+	llmOnly := RouterFunc(func(ctx context.Context, input router.NormalizedInput, now time.Time) (router.Decision, error) {
+		d, ok, err := lr.Route(ctx, input.Text, now)
 		if err != nil {
 			return d, err
 		}
@@ -152,8 +152,8 @@ func TestReachWithLLMRouter(t *testing.T) {
 	lr := router.NewLLMRouter(client)
 	m := router.DefaultActMatcher{Fns: actFns}
 
-	llmOnly := RouterFunc(func(ctx context.Context, u string, now time.Time) (router.Decision, error) {
-		d, ok, err := lr.Route(ctx, u, now)
+	llmOnly := RouterFunc(func(ctx context.Context, input router.NormalizedInput, now time.Time) (router.Decision, error) {
+		d, ok, err := lr.Route(ctx, input.Text, now)
 		if err != nil {
 			return d, err
 		}