feat(37-03): ChatVoicePlayer + ChatVoiceBadge components

- ChatVoicePlayer: POST /api/synthesize, play/pause controls, autoPlay support, blob URL cleanup
- ChatVoiceBadge: Voice badge, SPOKEN/DETAILED parsing, collapsible full markdown for voice_full

ui/src/components/ChatVoiceBadge.tsx

@@ -0,0 +1,51 @@
+import { useState } from "react";
+import { Badge } from "@/components/ui/badge";
+import {
+  Collapsible,
+  CollapsibleContent,
+  CollapsibleTrigger,
+} from "@/components/ui/collapsible";
+import { ChatVoicePlayer } from "./ChatVoicePlayer";
+import { ChatMarkdownMessage } from "./ChatMarkdownMessage";
+
+interface ChatVoiceBadgeProps {
+  content: string;
+  messageType: string; // "voice_input" | "voice_full"
+  autoPlayVoice?: boolean;
+}
+
+export function ChatVoiceBadge({
+  content,
+  messageType,
+  autoPlayVoice = false,
+}: ChatVoiceBadgeProps) {
+  const [open, setOpen] = useState(false);
+
+  const spokenMatch = content.match(/SPOKEN:\s*([\s\S]*?)(?=\nDETAILED:|$)/);
+  const spokenText = spokenMatch?.[1]?.trim() ?? content;
+  const detailedMatch = content.match(/DETAILED:\s*([\s\S]*)/);
+
+  return (
+    <div className="flex flex-col gap-1">
+      <Badge variant="outline" className="text-xs mb-2 w-fit">
+        Voice
+      </Badge>
+      <p className="text-sm">{spokenText}</p>
+      {messageType === "voice_full" && (
+        <>
+          <ChatVoicePlayer text={spokenText} autoPlay={autoPlayVoice} />
+          {detailedMatch && (
+            <Collapsible open={open} onOpenChange={setOpen}>
+              <CollapsibleTrigger className="text-xs text-muted-foreground hover:text-foreground mt-1">
+                {open ? "Hide full response" : "Show full response"}
+              </CollapsibleTrigger>
+              <CollapsibleContent>
+                <ChatMarkdownMessage content={detailedMatch[1].trim()} />
+              </CollapsibleContent>
+            </Collapsible>
+          )}
+        </>
+      )}
+    </div>
+  );
+}

ui/src/components/ChatVoicePlayer.tsx

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+import { useEffect, useRef, useState } from "react";
+import { Button } from "@/components/ui/button";
+import { Loader2, Pause, Play } from "lucide-react";
+
+interface ChatVoicePlayerProps {
+  text: string;
+  autoPlay?: boolean;
+}
+
+type PlayerStatus = "idle" | "loading" | "playing" | "paused";
+
+export function ChatVoicePlayer({ text, autoPlay = false }: ChatVoicePlayerProps) {
+  const [status, setStatus] = useState<PlayerStatus>("loading");
+  const [audioUrl, setAudioUrl] = useState<string | null>(null);
+  const audioRef = useRef<HTMLAudioElement | null>(null);
+
+  useEffect(() => {
+    let objectUrl: string | null = null;
+    let cancelled = false;
+
+    async function fetchAudio() {
+      setStatus("loading");
+      try {
+        const res = await fetch("/api/synthesize", {
+          method: "POST",
+          headers: { "Content-Type": "application/json" },
+          credentials: "include",
+          body: JSON.stringify({ text }),
+        });
+        if (cancelled) return;
+        if (!res.ok) {
+          setStatus("idle");
+          return;
+        }
+        const blob = await res.blob();
+        if (cancelled) return;
+        objectUrl = URL.createObjectURL(blob);
+        setAudioUrl(objectUrl);
+        setStatus("idle");
+      } catch {
+        if (!cancelled) {
+          setStatus("idle");
+        }
+      }
+    }
+
+    fetchAudio();
+
+    return () => {
+      cancelled = true;
+      if (objectUrl) {
+        URL.revokeObjectURL(objectUrl);
+      }
+    };
+  }, [text]);
+
+  useEffect(() => {
+    if (autoPlay && audioUrl && audioRef.current) {
+      audioRef.current.play().catch(() => {
+        // Browser may block autoplay; fall back to idle state
+        setStatus("idle");
+      });
+    }
+  }, [autoPlay, audioUrl]);
+
+  function handlePlay() {
+    if (audioRef.current) {
+      audioRef.current.play();
+    }
+  }
+
+  function handlePause() {
+    if (audioRef.current) {
+      audioRef.current.pause();
+    }
+  }
+
+  function handleAudioEnded() {
+    setStatus("idle");
+    if (audioUrl) {
+      URL.revokeObjectURL(audioUrl);
+      setAudioUrl(null);
+    }
+  }
+
+  if (status === "loading") {
+    return (
+      <span className="inline-flex items-center gap-1 text-xs text-muted-foreground">
+        <Loader2 className="h-3 w-3 animate-spin" />
+        Loading audio...
+      </span>
+    );
+  }
+
+  return (
+    <span className="inline-flex items-center">
+      {status === "playing" ? (
+        <Button variant="ghost" size="sm" onClick={handlePause} aria-label="Pause voice response">
+          <Pause className="h-3 w-3" />
+        </Button>
+      ) : (
+        <Button
+          variant="ghost"
+          size="sm"
+          onClick={handlePlay}
+          disabled={!audioUrl}
+          aria-label="Play voice response"
+        >
+          <Play className="h-3 w-3" />
+        </Button>
+      )}
+      <audio
+        ref={audioRef}
+        src={audioUrl ?? undefined}
+        aria-label="Voice response"
+        onPlay={() => setStatus("playing")}
+        onPause={() => setStatus("paused")}
+        onEnded={handleAudioEnded}
+      />
+    </span>
+  );
+}