feat(admin): add audio recorder UI skeleton (MediaRecorder) and embed into EditorShell

apps/admin/src/components/EditorShell.tsx

@@ -1,5 +1,6 @@
-import { Typography } from '@mui/material';
+import { Box, Typography } from '@mui/material';
 import AdminLayout from '../layout/AdminLayout';
+import Recorder from '../features/recorder/Recorder';
 
 export default function EditorShell({ onLogout }: { onLogout?: () => void }) {
   return (
@@ -7,9 +8,12 @@ export default function EditorShell({ onLogout }: { onLogout?: () => void }) {
       <Typography variant="h4" sx={{ mb: 2 }}>
         Welcome to VoxBlog Editor
       </Typography>
-      <Typography variant="body1">
-        Coming next: audio recorder, rich editor, AI tools, and Ghost publish flow.
-      </Typography>
+      <Box sx={{ display: 'grid', gap: 3 }}>
+        <Recorder />
+        <Typography variant="body1">
+          Coming next: rich editor, AI tools, and Ghost publish flow.
+        </Typography>
+      </Box>
     </AdminLayout>
   );
 }

apps/admin/src/features/recorder/Recorder.tsx

@@ -0,0 +1,76 @@
+import { useEffect, useRef, useState } from 'react';
+import { Box, Button, Stack, Typography } from '@mui/material';
+
+export default function Recorder() {
+  const mediaRecorderRef = useRef<MediaRecorder | null>(null);
+  const chunksRef = useRef<Blob[]>([]);
+  const [recording, setRecording] = useState(false);
+  const [audioUrl, setAudioUrl] = useState<string | null>(null);
+  const [error, setError] = useState<string>('');
+
+  const requestStream = async (): Promise<MediaStream | null> => {
+    try {
+      const stream = await navigator.mediaDevices.getUserMedia({ audio: true });
+      return stream;
+    } catch (e) {
+      setError('Microphone permission denied');
+      return null;
+    }
+  };
+
+  const startRecording = async () => {
+    setError('');
+    const stream = await requestStream();
+    if (!stream) return;
+
+    const mr = new MediaRecorder(stream);
+    mediaRecorderRef.current = mr;
+    chunksRef.current = [];
+
+    mr.ondataavailable = (e: BlobEvent) => {
+      if (e.data && e.data.size > 0) {
+        chunksRef.current.push(e.data);
+      }
+    };
+    mr.onstop = () => {
+      const blob = new Blob(chunksRef.current, { type: 'audio/webm' });
+      const url = URL.createObjectURL(blob);
+      setAudioUrl((prev) => {
+        if (prev) URL.revokeObjectURL(prev);
+        return url;
+      });
+      // stop all tracks to release mic
+      stream.getTracks().forEach(t => t.stop());
+    };
+
+    mr.start();
+    setRecording(true);
+  };
+
+  const stopRecording = () => {
+    mediaRecorderRef.current?.stop();
+    setRecording(false);
+  };
+
+  useEffect(() => {
+    return () => {
+      if (audioUrl) URL.revokeObjectURL(audioUrl);
+    };
+  }, [audioUrl]);
+
+  return (
+    <Box>
+      <Typography variant="h6" sx={{ mb: 1 }}>Audio Recorder</Typography>
+      <Stack direction="row" spacing={2} sx={{ mb: 2 }}>
+        <Button variant="contained" disabled={recording} onClick={startRecording}>Start</Button>
+        <Button variant="outlined" disabled={!recording} onClick={stopRecording}>Stop</Button>
+      </Stack>
+      {error && <Typography color="error" sx={{ mb: 2 }}>{error}</Typography>}
+      {audioUrl && (
+        <Box>
+          <audio controls src={audioUrl} />
+        </Box>
+      )}
+    </Box>
+  );
+}