the reply seam takes the turn's context (V-638)

voice.Replier.Reply had no context, so llmReplier phrased under
context.Background() and the only bound on a reply was phraser.timeout,
60s in deploy. Both call sites already held a context.

The stub ignores it: it makes no model call.

internal/voice/replier.go

@@ -26,6 +26,8 @@
 package voice
 
 import (
+	"context"
+
 	"github.com/kami/maven/internal/phraser"
 	"github.com/kami/maven/internal/router"
 )
@@ -38,8 +40,10 @@ import (
 // decision's Intent + Slots + Clarify. The Intent largely names the reply
 // shape (act/reminder/fact/note/query/clarify); the Slots carry the
 // specifics that personalise it ("got it: water at 14:00").
+// The context is the turn's, and it is the only bound an LLM-backed impl has
+// besides the phraser timeout (V-638). A floor impl ignores it.
 type Replier interface {
-	Reply(d router.Decision) string
+	Reply(ctx context.Context, d router.Decision) string
 }
 
 // StubReplier — the deterministic, no-model floor. Canned per intent;
@@ -54,7 +58,8 @@ func NewStubReplier() *StubReplier { return &StubReplier{} }
 
 // Reply dispatches on Intent + Clarify. Each branch is short; the LLM impl
 // will replace this with prompted text and the same dispatch shape.
-func (s *StubReplier) Reply(d router.Decision) string {
+// It makes no model call, so the context is unused.
+func (s *StubReplier) Reply(_ context.Context, d router.Decision) string {
 	if d.Clarify {
 		return "не совсем поняла — можешь переформулировать?"
 	}