v0.7.0a3

What's Changed

• feat: add ElevenLabs Conversational AI realtime provider
• Uses the official ElevenLabs SDK AsyncConversation with AsyncAudioInterface bridge
• Configuration: ElevenLabsRealtimeConfig with api_key, agent_id, requires_auth, base_url
• Runtime overrides: system prompt, voice, temperature, language via session metadata
• Tool calling via SDK's ClientTools mechanism
• Regional endpoint support (EU, India)
• Examples: local mic/speaker demo + tool calling demo
• Documentation in realtime-voice-providers guide

Full Changelog: v0.7.0a2...v0.7.0a3