Elevenlabs synthesize

[pragmatrix]

No description provided.

[Copilot]

Pull request overview

This PR adds ElevenLabs realtime streaming text-to-speech support and introduces partial text fragments (via an isFinal/is_final flag) so a single synthesis request can be streamed across multiple text events while preserving per-request completion semantics.

Changes:

• Extend the protocol (ClientEvent::Text → Input::Text) with an is_final flag (defaulting to true) to support partial text fragments.
• Add an ElevenLabs multi-context WebSocket synthesize service and register/export it alongside existing providers.
• Replace provider-specific synthesize examples with a single generic synthesize example, plus ADR/docs updates.

Reviewed changes

Copilot reviewed 19 out of 19 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
src/protocol.rs	Adds is_final to ClientEvent::Text with a serde default.
core/src/conversation.rs	Adds is_final to core Input::Text.
src/context_switch.rs	Plumbs is_final from protocol events into core input; registers ElevenLabs synthesize service.
src/lib.rs	Re-exports synthesize services (Azure/Aristech/ElevenLabs).
services/elevenlabs/src/lib.rs	Exposes new synthesize module and shared ws plumbing.
services/elevenlabs/src/ws.rs	Adds shared WebSocket writer/shutdown utilities for ElevenLabs realtime APIs.
services/elevenlabs/src/transcribe.rs	Refactors transcribe to use shared ws writer utilities.
services/elevenlabs/src/synthesize.rs	Implements ElevenLabs multi-context realtime TTS with partial-fragment support.
services/playback/src/lib.rs	Updates Input::Text handling for the new is_final field and forwards synthesize requests.
examples/synthesize.rs	Adds a unified synthesize example supporting Azure/ElevenLabs/Aristech + voice listing + interactive partial fragments.
examples/azure-synthesize.rs	Removed in favor of the generic synthesize example.
examples/aristech-synthesize.rs	Removed in favor of the generic synthesize example.
README.md	Updates example commands to the new generic synthesize example.
docs/adr/0002-partial-text-input.md	ADR documenting isFinal-based partial text fragments.
docs/adr/0003-elevenlabs-multi-context-synthesis.md	ADR documenting ElevenLabs multi-context design for request boundaries.
CONTEXT.md	Adds protocol glossary entry for “Partial Text”.
Cargo.toml	Bumps workspace version; adds aristech-tts-client for voice listing in example.
.harper-dictionary.txt	Adds “ElevenLabs” / “camelCase” to dictionary.
.github/copilot-instructions.md	Adds an explicit YAGNI section.