- Add gemini-3-flash to MODEL_FALLBACK_MAP for completeness - Add hasGeminiHistory() to detect Gemini→Claude cross-model switch - Trigger recovery for Claude only when Gemini history detected - Remove unnecessary thinking block filtering for Claude-only conversations - Add comments explaining '.' placeholder usage - Remove unused filterUnsignedThinkingFromMessages function 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-Authored-By: Claude <noreply@anthropic.com>