feat: {response,mood} output contract + router removal, TTS piper plan

Daemon side of Decision B: parse {"response","mood"} across the 4 consumers
(replier, nudges, reminders, chat), fall back to legacy formats. Drop the
LLM router — the classifier handles routing; replier/phraser share one
llm.Client (timeout 20s->60s). llm.Client reads reasoning_content when
content is empty (thinking models).

Docs: TTS piper-student plan (OmniVoice teacher -> piper student, from
scratch, phoneme-first). CLAUDE.md training guide.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

internal/llm/client.go

@@ -35,8 +35,10 @@ type Req struct {
 }
 
 type msg struct {
-	Role    string `json:"role"`
-	Content string `json:"content"`
+	Role             string `json:"role"`
+	Content          string `json:"content"`
+	Reasoning        string `json:"reasoning,omitempty"`
+	ReasoningContent string `json:"reasoning_content,omitempty"`
 }
 type body struct {
 	Messages      []msg    `json:"messages"`
@@ -54,7 +56,7 @@ type resp struct {
 
 func (c *Client) Complete(ctx context.Context, r Req) (string, error) {
 	b, _ := json.Marshal(body{
-		Messages:      []msg{{"system", r.System}, {"user", r.User}},
+		Messages:      []msg{{Role: "system", Content: r.System}, {Role: "user", Content: r.User}},
 		MaxTokens:     r.MaxTokens,
 		Grammar:       r.Grammar,
 		Temp:          0,
@@ -81,5 +83,9 @@ func (c *Client) Complete(ctx context.Context, r Req) (string, error) {
 	if len(out.Choices) == 0 {
 		return "", fmt.Errorf("llm: no choices")
 	}
-	return out.Choices[0].Message.Content, nil
+	content := out.Choices[0].Message.Content
+	if content == "" {
+		content = out.Choices[0].Message.ReasoningContent
+	}
+	return content, nil
 }