Synchronous virtual classrooms are often evaluated as communication technologies, yet their educational value depends on how social, cognitive, participatory, and reflective processes are coordinated across a live session and its aftermath. This paper develops a theory-grounded design science framework for AI-augmented synchronous learning orchestration and instantiates the framework through EZoom, a self-hosted browser-based virtual classroom artefact. Drawing on recent evidence concerning teaching and social presence, active-learning participation, interaction-related cognitive load, formative retrieval, generative-AI-supported summarisation, and educational data governance, the study develops the Presence-Participation-Reflection Orchestration (PPRO) framework. The framework proposes that teaching presence and social presence create the conditions for participation; that participation quality, rather than raw interaction volume, mediates the educational value of synchronous activity; that excessive simultaneous interaction demands can increase cognitive load and weaken this relationship; and that educator-controlled post-session reflection can extend synchronous activity into consolidation and retrieval. Data-governance trust is treated as an institutional boundary condition rather than a direct pedagogical outcome. The EZoom source artefact is analysed to examine how these theoretical mechanisms can be operationalised through integrated WebRTC/WebSocket communication, waiting-room governance, chat, Q&A, polls, whiteboard state, screen sharing, local recording, session reporting, and optional Gemini-generated notes and quizzes. The paper does not claim causal learning effects from the artefact itself. Instead, it contributes a theory-to-architecture mapping, six testable propositions, a source-traceable technical analysis, and a mixed-method evaluation protocol for subsequent field validation. The resulting framework shifts evaluation from feature accumulation toward theoretically specified orchestration:
how platform design sequences presence, participation, and reflection while managing cognitive load,
educator control, AI provenance, and privacy boundaries.