ConflictDetector._checkAttendeeConflicts uses O(n*m) nested loop

[thedhanawada]

Description

ConflictDetector._checkAttendeeConflicts() (lines 325-332 in core/conflicts/ConflictDetector.js) uses nested for-loops to find overlapping attendees:

for (const attendee1 of event1.attendees) {
    for (const attendee2 of event2.attendees) {
        if (attendee1.email === attendee2.email) {
            conflictingAttendees.push(attendee1.email);
        }
    }
}

This is O(n*m) where n and m are attendee counts.

Impact

• Enterprise events can have 50-100+ attendees
• Conflict detection is called for every event pair in a time range
• For a day with 20 events averaging 50 attendees each, this results in 190 pair checks * 2500 comparisons = 475,000 email comparisons
• Noticeable UI lag on conflict detection in enterprise environments

Expected Fix

Use a Set for O(1) lookup:

const emails1 = new Set(event1.attendees.map(a => a.email));
const conflicting = event2.attendees.filter(a => emails1.has(a.email));

Files

• core/conflicts/ConflictDetector.js:325-332