feat: add homeai-desktop web assistant with LAN access

Adds the desktop web assistant app (Vite + React) with OpenClaw bridge
proxy and exposes it on the local network (host: 0.0.0.0, port 5174).

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

homeai-desktop/src/lib/audio.js

@@ -0,0 +1,103 @@
+const TARGET_RATE = 16000
+
+/**
+ * Record audio from the microphone, returning a WAV blob when stopped.
+ * Returns { start, stop } — call start() to begin, stop() resolves with a Blob.
+ */
+export function createRecorder() {
+  let audioCtx
+  let source
+  let processor
+  let stream
+  let samples = []
+
+  async function start() {
+    samples = []
+    stream = await navigator.mediaDevices.getUserMedia({
+      audio: { channelCount: 1, sampleRate: TARGET_RATE },
+    })
+    audioCtx = new AudioContext({ sampleRate: TARGET_RATE })
+    source = audioCtx.createMediaStreamSource(stream)
+
+    // ScriptProcessorNode captures raw Float32 PCM
+    processor = audioCtx.createScriptProcessor(4096, 1, 1)
+    processor.onaudioprocess = (e) => {
+      const input = e.inputBuffer.getChannelData(0)
+      samples.push(new Float32Array(input))
+    }
+    source.connect(processor)
+    processor.connect(audioCtx.destination)
+  }
+
+  async function stop() {
+    // Stop everything
+    processor.disconnect()
+    source.disconnect()
+    stream.getTracks().forEach((t) => t.stop())
+    await audioCtx.close()
+
+    // Merge all sample chunks
+    const totalLength = samples.reduce((acc, s) => acc + s.length, 0)
+    const merged = new Float32Array(totalLength)
+    let offset = 0
+    for (const chunk of samples) {
+      merged.set(chunk, offset)
+      offset += chunk.length
+    }
+
+    // Resample if the actual sample rate differs from target
+    const resampled = audioCtx.sampleRate !== TARGET_RATE
+      ? resample(merged, audioCtx.sampleRate, TARGET_RATE)
+      : merged
+
+    // Convert to 16-bit PCM WAV
+    return encodeWav(resampled, TARGET_RATE)
+  }
+
+  return { start, stop }
+}
+
+function resample(samples, fromRate, toRate) {
+  const ratio = fromRate / toRate
+  const newLength = Math.round(samples.length / ratio)
+  const result = new Float32Array(newLength)
+  for (let i = 0; i < newLength; i++) {
+    result[i] = samples[Math.round(i * ratio)]
+  }
+  return result
+}
+
+function encodeWav(samples, sampleRate) {
+  const numSamples = samples.length
+  const buffer = new ArrayBuffer(44 + numSamples * 2)
+  const view = new DataView(buffer)
+
+  // WAV header
+  writeString(view, 0, 'RIFF')
+  view.setUint32(4, 36 + numSamples * 2, true)
+  writeString(view, 8, 'WAVE')
+  writeString(view, 12, 'fmt ')
+  view.setUint32(16, 16, true) // chunk size
+  view.setUint16(20, 1, true) // PCM
+  view.setUint16(22, 1, true) // mono
+  view.setUint32(24, sampleRate, true)
+  view.setUint32(28, sampleRate * 2, true) // byte rate
+  view.setUint16(32, 2, true) // block align
+  view.setUint16(34, 16, true) // bits per sample
+  writeString(view, 36, 'data')
+  view.setUint32(40, numSamples * 2, true)
+
+  // PCM data — clamp Float32 to Int16
+  for (let i = 0; i < numSamples; i++) {
+    const s = Math.max(-1, Math.min(1, samples[i]))
+    view.setInt16(44 + i * 2, s < 0 ? s * 0x8000 : s * 0x7fff, true)
+  }
+
+  return new Blob([buffer], { type: 'audio/wav' })
+}
+
+function writeString(view, offset, str) {
+  for (let i = 0; i < str.length; i++) {
+    view.setUint8(offset + i, str.charCodeAt(i))
+  }
+}