Nenya 0.8.0

Changelog

• c29e77b Merge phase-010: Context-overflow patterns + HTTP 529 retry
• 6de207a Merge phase-011: Model version detection utility
• 1d12541 Merge phase-012: Adaptive thinking for Anthropic
• a34ed2d Merge phase-013: xAI reasoning_effort injection
• 57370ab Merge phase-014: Strip bare reasoning field
• bb5b9f2 Merge phase-015: Prompt cache key injection
• 4e3093b Merge phase-016: Reasoning token usage tracking
• e698851 feat(anthropic): add adaptive thinking support for newer Anthropic models
• 776c939 feat(cache): inject prompt_cache_key for xai/openai providers
• 59802cf feat(metrics): add reasoning token tracking to streaming path
• 371f22b feat(routing): strip non-standard bare reasoning field
• bed9962 feat(util): add Anthropic model version detection utility
• 535873f feat(xai): inject reasoning_effort for reasoning-capable Grok models
• f3a636f fix(format): align constant declarations with gofmt
• 584e846 fix(metrics): address reasoning token tracking bugs found in review
• b87c69f fix(proxy): expand context-overflow patterns and add HTTP 529 retry
• a045758 fix(resilience): restore missing context-limit error patterns
• 811288c fix(review): add hex validation for OpenAI cache key test
• a212b5d fix(review): address Phase 012 review findings
• dec4225 fix(review): address Phase 013 review findings
• 21a50ff fix(review): address Phase 014 review findings