* perf: optimize slot conflict checking from O(n²) to O(n log n) - Replace nested mapping with pre-sorted busy slots for faster lookups - Use early termination when busy slots are sorted by start time - Maintain exact same interface and behavior as original checkForConflicts - All existing tests pass, preserving edge case handling - Reduces complexity from O(available slots × busy slots) to O(n log n) Co-Authored-By: keith@cal.com <keithwillcode@gmail.com> * refactor: move O(n log n) optimization to checkForConflicts function - Replace inline optimization with optimized checkForConflicts function - Maintain same performance while improving code architecture - Avoid duplication of conflict checking logic - Keep all existing interfaces and behavior unchanged Co-Authored-By: keith@cal.com <keithwillcode@gmail.com> * test: add comprehensive unit tests for checkForConflicts function - Add 20 additional test cases covering edge cases and boundary conditions - Test multiple busy periods scenarios and complex overlaps - Comprehensive currentSeats handling scenarios - Timezone and cross-day boundary testing - Performance testing with large datasets - Fix invalid date generation in test data that was causing NaN conflicts - Achieve near 100% coverage of all conflict scenarios documented in function comments - Verify behavioral equivalence between original O(n²) and optimized O(n log n) implementations Co-Authored-By: keith@cal.com <keithwillcode@gmail.com> * Simple, safe performance tweak * Explicitly define the input of busy to be either Date or Dayjs, not string * EventBusyDate must ALWAYS be a type that supports valueOf * Revert "EventBusyDate must ALWAYS be a type that supports valueOf" This reverts commit 35b572266219d64c22db3c3e24b0cb6ca7a901a6. * Revert "Explicitly define the input of busy to be either Date or Dayjs, not string" This reverts commit 902f29708e4b7990a4e5e2865cab2f18ab3e44f0. --------- Co-authored-by: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com> Co-authored-by: Alex van Andel <me@alexvanandel.com>