feat: Add voice assistant handler and Kubeflow pipeline

- voice_assistant.py: Standalone NATS handler with full RAG pipeline
- voice_assistant_v2.py: Handler-base implementation
- pipelines/voice_pipeline.py: KFP SDK pipeline definitions
- Dockerfiles for both standalone and handler-base versions

Pipeline: STT → Embeddings → Milvus → Rerank → LLM → TTS

README.md

@@ -1,3 +1,120 @@
-# voice-assistant
+# Voice Assistant
 
-voice assistance please
+End-to-end voice assistant pipeline for the DaviesTechLabs AI/ML platform.
+
+## Components
+
+### Real-time Handler (NATS-based)
+
+The voice assistant service listens on NATS for audio requests and returns synthesized speech responses.
+
+**Pipeline:** STT → Embeddings → Milvus RAG → Rerank → LLM → TTS
+
+| File | Description |
+|------|-------------|
+| `voice_assistant.py` | Standalone handler (v1) |
+| `voice_assistant_v2.py` | Handler using handler-base library |
+| `Dockerfile` | Standalone image |
+| `Dockerfile.v2` | Handler-base image |
+
+### Kubeflow Pipeline (Batch)
+
+For batch processing or async workflows via Kubeflow Pipelines.
+
+| Pipeline | Description |
+|----------|-------------|
+| `voice_pipeline.yaml` | Full STT → RAG → TTS pipeline |
+| `rag_pipeline.yaml` | Text-only RAG pipeline |
+| `tts_pipeline.yaml` | Simple text-to-speech |
+
+```bash
+# Compile pipelines
+cd pipelines
+pip install kfp==2.12.1
+python voice_pipeline.py
+```
+
+## Architecture
+
+```
+NATS (voice.request)
+        │
+        ▼
+┌───────────────────┐
+│  Voice Assistant  │
+│    Handler        │
+└───────────────────┘
+        │
+        ├──▶ Whisper STT (elminster)
+        │         │
+        │         ▼
+        ├──▶ BGE Embeddings (drizzt)
+        │         │
+        │         ▼
+        ├──▶ Milvus Vector Search
+        │         │
+        │         ▼
+        ├──▶ BGE Reranker (danilo)
+        │         │
+        │         ▼
+        ├──▶ vLLM (khelben)
+        │         │
+        │         ▼
+        └──▶ XTTS TTS (elminster)
+                  │
+                  ▼
+         NATS (voice.response.{id})
+```
+
+## Configuration
+
+| Environment Variable | Default | Description |
+|---------------------|---------|-------------|
+| `NATS_URL` | `nats://nats.ai-ml.svc.cluster.local:4222` | NATS server |
+| `WHISPER_URL` | `http://whisper-predictor.ai-ml.svc.cluster.local` | STT service |
+| `EMBEDDINGS_URL` | `http://embeddings-predictor.ai-ml.svc.cluster.local` | Embeddings |
+| `RERANKER_URL` | `http://reranker-predictor.ai-ml.svc.cluster.local` | Reranker |
+| `VLLM_URL` | `http://llm-draft.ai-ml.svc.cluster.local:8000` | LLM service |
+| `TTS_URL` | `http://tts-predictor.ai-ml.svc.cluster.local` | TTS service |
+| `MILVUS_HOST` | `milvus.ai-ml.svc.cluster.local` | Vector DB |
+| `COLLECTION_NAME` | `knowledge_base` | Milvus collection |
+
+## NATS Message Format
+
+### Request (voice.request)
+
+```json
+{
+  "request_id": "uuid",
+  "audio": "base64-encoded-audio",
+  "language": "en",
+  "collection": "knowledge_base"
+}
+```
+
+### Response (voice.response.{request_id})
+
+```json
+{
+  "request_id": "uuid",
+  "transcription": "user question",
+  "response": "assistant answer",
+  "audio": "base64-encoded-audio"
+}
+```
+
+## Building
+
+```bash
+# Standalone image (v1)
+docker build -f Dockerfile -t voice-assistant:latest .
+
+# Handler-base image (v2 - recommended)
+docker build -f Dockerfile.v2 -t voice-assistant:v2 .
+```
+
+## Related
+
+- [homelab-design](https://git.daviestechlabs.io/daviestechlabs/homelab-design) - Architecture docs
+- [kuberay-images](https://git.daviestechlabs.io/daviestechlabs/kuberay-images) - Ray worker images
+- [handler-base](https://github.com/Billy-Davies-2/llm-workflows/tree/main/handler-base) - Base handler library