feat: BreakPilot PWA - Full codebase (clean push without large binaries)

All services: admin-v2, studio-v2, website, ai-compliance-sdk,
consent-service, klausur-service, voice-service, and infrastructure.
Large PDFs and compiled binaries excluded via .gitignore.

backend/classroom/services/__init__.py

@@ -0,0 +1,23 @@
+"""
+Classroom Services Package
+"""
+
+from .persistence import (
+    init_db_if_needed,
+    load_active_sessions_from_db,
+    persist_session,
+    get_session_or_404,
+    DB_ENABLED,
+    sessions,
+    SessionLocal,
+)
+
+__all__ = [
+    "init_db_if_needed",
+    "load_active_sessions_from_db",
+    "persist_session",
+    "get_session_or_404",
+    "DB_ENABLED",
+    "sessions",
+    "SessionLocal",
+]