v6.9.6

Changelog

• 1587ff5 Merge pull request router-for-me#2389 from router-for-me/claude
• 6570692 Merge pull request router-for-me#2400 from router-for-me/revert-2374-codex-cache-clean
• 13aa5b3 Revert "fix(codex): restore prompt cache continuity for Codex requests"
• 6d8de0a feat(auth): implement weighted provider rotation for improved scheduling fairness
• 145e0e0 fix(claude): add default max_tokens for models
• f033d3a fix(claude): enhance ensureModelMaxTokens to use registered max_completion_tokens and fallback to default