chore: bootstrap hermes-ui skeleton from 0.6.29 snapshot

Import the client, server, skills, tests, and build scripts as the starting
point for the rebuild, then trim the surfaces this project does not ship:
Electron desktop packaging, the marketing website, and the ESP32 firmware
tree. CI keeps the web build, e2e, lockfile, release, and Docker workflows.

Rename the package and CLI entry points to hermes-ui, drop the prepare hook so
npm ci no longer triggers a build, and drop the removed tsconfig and nodemon
references. Rewrite AGENTS.md, ARCHITECTURE.md, DEVELOPMENT.md, and the READMEs
so the documented package map and hard rules match this repository.

reference_code/ is ignored: it is a read-only snapshot, not an input to the build.

tests/server/audio-convert.test.ts

@@ -0,0 +1,45 @@
+import { describe, expect, it } from 'vitest'
+
+import { transcodeToPcmS16le } from '../../packages/server/src/services/hermes/stt-providers/audio-convert'
+
+function wavS16le(samples: number[], sampleRate: number, channels = 1): Buffer {
+  const dataSize = samples.length * 2
+  const header = Buffer.alloc(44)
+  header.write('RIFF', 0)
+  header.writeUInt32LE(36 + dataSize, 4)
+  header.write('WAVE', 8)
+  header.write('fmt ', 12)
+  header.writeUInt32LE(16, 16)
+  header.writeUInt16LE(1, 20)
+  header.writeUInt16LE(channels, 22)
+  header.writeUInt32LE(sampleRate, 24)
+  header.writeUInt32LE(sampleRate * channels * 2, 28)
+  header.writeUInt16LE(channels * 2, 32)
+  header.writeUInt16LE(16, 34)
+  header.write('data', 36)
+  header.writeUInt32LE(dataSize, 40)
+
+  const data = Buffer.alloc(dataSize)
+  samples.forEach((sample, index) => {
+    data.writeInt16LE(sample, index * 2)
+  })
+  return Buffer.concat([header, data])
+}
+
+describe('audio-convert', () => {
+  it('decodes WAV to MCU PCM without ffmpeg', async () => {
+    const wav = wavS16le([0, 16384, -16384, 0], 8000)
+
+    const result = await transcodeToPcmS16le(wav, 'audio/wav', { sampleRate: 16000 })
+
+    expect(result.mimeType).toBe('audio/x-pcm')
+    expect(result.fileName).toBe('audio.pcm')
+    expect(result.audio.length).toBe(16)
+  })
+
+  it('rejects unsupported MCU PCM decode formats', async () => {
+    await expect(
+      transcodeToPcmS16le(Buffer.from('not audio'), 'audio/ogg', { sampleRate: 16000 }),
+    ).rejects.toThrow('unsupported audio format for MCU PCM decode')
+  })
+})