refactor(providers): 🔨 improve error handling and logging specificity

fix(auth): 🔨 prioritize file-based credential loading over environment variables

feat(io): ✨ add shutdown flush mechanism for buffered writes

feat(io): ✨ add fault-tolerant file operations with automatic recovery

Merge origin/main into feat/runtime-resilience - Resolve conflict in usage_manager.py by integrating runtime resilience with human-readable timestamps

Merge branch 'main' into fix/antigravity-credential-stuck-unavailable

Fix to satisfy pylint

refactor(auth): 🔨 relocate attribute declarations in BackgroundRefresher

fix(auth): 🐛 improve credential refresh detection and prevent queue processor stuck state

feat(auth): ✨ implement global reauth coordinator to serialize interactive OAuth flows

refactor(providers): 🔨 improve error handling and reduce debug logging in antigravity provider

fix(providers): disable endpoint in antigravity provider

refactor(client): 🔨 add comprehensive error handling and retry logic for custom provider non-streaming calls

feat(concurrency): ✨ add priority-based concurrency multipliers for credential tiers

fix - addressing review findings.

feat(usage): ✨ add human-readable timestamp fields to usage data for debugging

fix(google-oauth): prevent credentials from becoming permanently stuck

fix(resilience): complete circuit breaker patterns per PR review

refactor(providers): 🔨 centralize tier and quota configuration in ProviderInterface

feat: add runtime resilience for file deletion survival

refactor(usage): 🔨 cache provider plugin instances to reduce redundant instantiation

refactor(client): 🔨 initialize provider plugins before rotation mode detection

feat(usage): ✨ implement per-model quota tracking with authoritative reset timestamps

feat(usage): ✨ add provider-specific rolling window usage tracking

feat(rotation): ✨ add sequential rotation mode with provider-specific quota parsing

feat(providers): ✨ implement credential tier initialization and persistence system

fix(error-handler): 🔨 extract JSON retry parsing into dedicated function

fix(antigravity-provider): handle multiple consecutive system messages in prompt processing

fix(error-handler): 🐛 handle compound duration formats in retry-after parsing

Merge pull request #21 from MasuRii/fix/quota-exceeded-global-cooldown

Merge branch 'main' into Antigravity

docs(antigravity): 📚 update documentation for credential prioritization and model support changes

feat(antigravity): ✨ implement credential prioritization for tier-based routing

fix(oauth): 🐛 escape rich markup in oauth authorization urls

fix(antigravity): 🐛 prevent unescaping of intentional quotes and backslashes in strings

docs: 📚 update documentation for enhanced claude thinking sanitization and remove obsolete todo file

fix(antigravity): 🐛 improve function call response pairing with recovery strategies

refactor(antigravity): 🔨 migrate thinking sanitization to gemini message format

refactor(antigravity-claude): refactor the claude sanitization logic to prevent errors on compaction, model switching, and allow thinking.

fix(provider): 🐛 ensure claude-opus-4-5 always uses thinking variant

Merge branch 'Antigravity' of https://github.com/Mirrowel/LLM-API-Key-Proxy into fix/quota-exceeded-global-cooldown

feat(provider): add support for Claude Opus 4.5 model

fix(rotator): prevent quota errors from global cooldown

fix(logging): preserve full credential filenames in logs

fix(provider): 🐛 increase timeout for antigravity API requests from 120s to 600s

Merge pull request #14 from Mirrowel/Error-handling-consistency

fix: improve error handling implementation based on code review

feat(provider): ✨ implement Google Cloud onboarding flow with automatic project discovery

refactor(provider): 🔨 replace hardcoded project generation with dynamic GCP resolution

feat(core): ✨ add structured error accumulator and consistent error handling/reporting