fix: Restore all files lost during destructive rebase

A previous `git pull --rebase origin main` dropped 177 local commits,
losing 3400+ files across admin-v2, backend, studio-v2, website,
klausur-service, and many other services. The partial restore attempt
(660295e2) only recovered some files.

This commit restores all missing files from pre-rebase ref 98933f5e
while preserving post-rebase additions (night-scheduler, night-mode UI,
NightModeWidget dashboard integration).

Restored features include:
- AI Module Sidebar (FAB), OCR Labeling, OCR Compare
- GPU Dashboard, RAG Pipeline, Magic Help
- Klausur-Korrektur (8 files), Abitur-Archiv (5+ files)
- Companion, Zeugnisse-Crawler, Screen Flow
- Full backend, studio-v2, website, klausur-service
- All compliance SDKs, agent-core, voice-service
- CI/CD configs, documentation, scripts

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

docker/jibri/start-xvfb.sh

@@ -0,0 +1,26 @@
+#!/bin/bash
+# Start Xvfb (Virtual Framebuffer) for Jibri recording
+
+set -e
+
+DISPLAY_NUM="${DISPLAY_NUM:-0}"
+RESOLUTION="${RESOLUTION:-1920x1080x24}"
+
+echo "[Xvfb] Starting virtual display :${DISPLAY_NUM} with resolution ${RESOLUTION}"
+
+# Remove any existing lock files
+rm -f /tmp/.X${DISPLAY_NUM}-lock
+
+# Start Xvfb in background
+Xvfb :${DISPLAY_NUM} -screen 0 ${RESOLUTION} -ac +extension GLX +render -noreset &
+
+# Wait for Xvfb to start
+sleep 2
+
+# Verify display is working
+if xdpyinfo -display :${DISPLAY_NUM} >/dev/null 2>&1; then
+    echo "[Xvfb] Display :${DISPLAY_NUM} is ready"
+else
+    echo "[Xvfb] ERROR: Display :${DISPLAY_NUM} failed to start"
+    exit 1
+fi