grammar: the last two model calls that were still free text

The replier and the meeting summariser were the two call sites without a
GBNF. Both are exactly the shape that makes a Thinking variant answer with
its reasoning as prose, and neither had anything downstream that could
remove it.

The replier already parses {"response","mood"}, so it now sends the phraser's
grammar for that contract, exported once as phraser.ResponseGrammar so the
two definitions cannot drift.

The summariser stays text-in/text-out. The JSON wrapper is attached and
unwrapped in the daemon's Completer, so internal/capture is unchanged and a
Completer without a grammar still works.

The simulator told routing from phrasing by "has a grammar", which stopped
being true here; it now looks for the intent enum.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

cmd/mavend/replier_llm.go

@@ -8,6 +8,7 @@ import (
 
 	"github.com/kami/maven/internal/llm"
 	"github.com/kami/maven/internal/persona"
+	"github.com/kami/maven/internal/phraser"
 	"github.com/kami/maven/internal/router"
 	"github.com/kami/maven/internal/voice"
 )
@@ -47,6 +48,7 @@ func (r *llmReplier) Reply(d router.Decision) string {
 	out, err := r.c.Complete(ctx, llm.Req{
 		System:        persona.Prepend(r.block, replySystem),
 		User:          replyContext(d),
+		Grammar:       phraser.ResponseGrammar,
 		MaxTokens:     512,
 		RepeatPenalty: 1.3,
 	})