Modernizing eventyay-flowspace: Migrating to Vue 3 with Modern Jitsi Integration

Online conferences are efficient for content delivery, but they still struggle to recreate one core part of in-person events: informal social spaces. Hallway conversations, spontaneous meetups, and unplanned networking moments are often where the most meaningful connections happen. eventyay-flowspace is designed to restore this missing layer by providing a spatial, proximity-based social lounge tightly integrated with Eventyay. The current legacy baseline has major limitations: it is unmaintained, built on Create React App, and depends on the global `window.JitsiMeetJS` integration patterns that are hard to isolate and test.