Add ToolReferenceChunk, ToolFileChunk, BuiltInConnector enum,
ReferenceID union type (int|string), GuardrailConfig with v1/v2
moderation, ConnectorTool for custom connectors, and guardrails
field on chat/agents/conversation requests.
Add AudioTranscriptionRealtime and AudioSpeech to ModelCapabilities.
Move GuardrailConfig from agents/ to chat/ as shared base type.
Remove bundled OpenAPI spec; SDK now tracks upstream Python SDK.
BREAKING: ReferenceChunk.ReferenceIDs changed from []int to
[]ReferenceID. Use IntRef(n) / StringRef(s) constructors.
1. Add README, LICENSE (MIT), .gitignore, Makefile, CHANGELOG
2. Add Version constant and User-Agent header to all requests
3. Rename SetStream to EnableStream (narrower API surface)
4. Fix FinishReason in CompletionStreamChoice to use typed *FinishReason
5. Type conversation entry Content as chat.Content instead of json.RawMessage
6. Graceful unknown type handling — UnknownEntry, UnknownEvent,
UnknownChunk, UnknownMessage, UnknownAgentTool all return data
instead of erroring on unrecognized discriminator values
7. Type agent tools with AgentTool sealed interface + UnmarshalAgentTool
8. Add pagination params to ListConversations and ListLibraries
9. Move openapi.yaml to docs/openapi.yaml
