refactor(core): 🔨 centralize path management for PyInstaller compatibility

refactor(timeout): 🔨 centralize HTTP timeout configuration across providers

fix(httpx): set custom timeout for all POST requests

fix(providers): 🐛 improve finish_reason handling and tool_calls initialization in stream reassembly

feat(providers): implement detailed file logging for iFlow and Qwen Code

refactor(providers): enhance model discovery and deduplication logic

feat(auth): enable Qwen and iFlow credential export and dynamic model discovery

refactor(auth): enhance token refresh stability and resilience

feat(auth): enable API key fallback for Qwen Code and iFlow providers

feat(auth): introduce iFlow provider integration via OAuth

refactor(providers): overhaul qwen code provider for custom streaming

fix(core): stabilize streaming for custom endpoints and eliminate initialization conflicts

refactor: improve model registration and usage manager robustness

refactor(auth): generalize credential handling and improve model matching

refactor(client): simplify completion flow by removing internal streaming logic

feat(auth): implement robust OAuth credential initialization and management

feat(provider): introduce OAuth credential management and custom provider handling