- Updated `defaultAntigravityAgent` to version `1.11.5`.
- Adjusted const value formatting for improved readability.
**feat(executor): introduce fallback mechanism for Antigravity base URLs**
- Added retry logic with fallback order for Antigravity base URLs to handle request errors and rate limits.
- Refactored base URL handling with `antigravityBaseURLFallbackOrder` and related utilities.
- Enhanced error handling in non-streaming and streaming requests with retry support and improved metadata reporting.
- Updated `buildRequest` to support dynamic base URL assignment.
- Improved Antigravity executor to handle `thinkingConfig` adjustments and default `thinkingBudget` when `thinkingLevel` is removed.
- Updated translator response handling to set default values for output token counts when specific token data is missing.
- Introduced `modelName2Alias` and `alias2ModelName` functions for mapping between model names and aliases.
- Improved Antigravity payload transformation to include alias-to-model name conversion.
- Enhanced processing for Claude Sonnet models to adjust template parameters based on schema presence.
- Introduced request and response translation functions to enable compatibility between OpenAI Chat Completions API and Antigravity.
- Registered translation utilities for both streaming and non-streaming scenarios.
- Added support for reasoning content, tool calls, and metadata handling.
- Established request normalization and embedding for Antigravity-compatible payloads.
- Added new fields to `Params` struct for better tracking of finish reasons, usage metadata, and tool usage.
- Refactored handling of response transitions, final events, and state-driven logic in `ConvertAntigravityResponseToClaude`.
- Introduced `appendFinalEvents` and `resolveStopReason` helper functions for cleaner separation of concerns.
- Added `TotalTokenCount` field to `Params` struct for enhanced token tracking.
- Updated token count calculations to fallback on `TotalTokenCount` when specific counts are missing.
- Introduced `hasNonZeroUsageMetadata` function to validate presence of token data in `usage_metadata`.
- Implemented OAuth login flow for the Antigravity provider in `auth/antigravity.go`.
- Added `AntigravityExecutor` for handling requests and streaming via Antigravity APIs.
- Created `antigravity_login.go` command for triggering Antigravity authentication.
- Introduced OpenAI-to-Antigravity translation logic in `translator/antigravity/openai/chat-completions`.
**refactor(translator, executor): update Gemini CLI response translation and add Antigravity payload customization**
- Renamed Gemini CLI translation methods to align with response handling (`ConvertGeminiCliResponseToGemini` and `ConvertGeminiCliResponseToGeminiNonStream`).
- Updated `init.go` to reflect these method changes.
- Introduced `geminiToAntigravity` function to embed metadata (`model`, `userAgent`, `project`, etc.) into Antigravity payloads.
- Added random project, request, and session ID generators for enhanced tracking.
- Streamlined `buildRequest` to use `geminiToAntigravity` transformation before request execution.
