XFEstudio/gpt4free

refactor: reorganize providers and update model configurations

- Rename DeepInfraChat to DeepInfra across all files - Move DeepInfra from needs_auth to main Provider directory - Rename LMArenaBeta to LMArena throughout codebase - Move search-related providers to new search subdirectory (GoogleSearch, SearXNG, YouTube) - Move deprecated providers to not_working directory (Free2GPT, LegacyLMArena, PenguinAI, ImageLabs, har) - Add new Mintlify provider with custom AI assistant implementation - Update Anthropic provider with Claude 4 models and Opus 4.1 parameter handling - Update Grok provider with Grok 4 models and improved streaming support - Update GithubCopilot with expanded model list including o3-mini, o4-mini, gpt-5 previews - Update LambdaChat default model from deepseek-r1 to deepseek-llama3.3-70b - Update TeachAnything default model from gemini-1.5-pro to gemma - Remove DeepInfra from needs_auth directory - Update all model_map references from DeepInfraChat to DeepInfra - Update all model_map references from LMArenaBeta to LMArena - Add beta_headers support to Anthropic for special features - Improve Mintlify provider with system prompt handling and streaming - Update model configurations in models.py to reflect provider changes