Add voiced NPC dialogue using Fish Audio

## Context
From ThursdAI podcast (March 19, 2026) — Fish Audio is an open-source, real-time, emotion-controllable voice cloning/TTS system.

## What
Integrate Fish Audio for voiced NPC dialogue and narration in HunterPath.

## Why
- **Open source** — no vendor lock-in
- **Emotion tags** — free-form tags like `[whisper]`, `[gasp]`, `[excited]` in the text (not limited to presets)
- **Real-time** generation — fast enough for gameplay
- **Multi-speaker** — different voices per NPC
- **Voice cloning** — create unique character voices from short samples

## Resources
- Website: https://fish.audio
- Alternative: Groq TTS API (hosted, faster latency, cheaper than 11 Labs, 5 voices, multilingual)

## Tasks
- [ ] Evaluate Fish Audio vs Groq TTS for latency/quality trade-offs
- [ ] Design NPC dialogue system that supports optional voice playback
- [ ] Create voice profiles for key NPCs
- [ ] Add audio playback to dialogue UI component