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>

backend/ai_processor.py

@@ -0,0 +1,81 @@
+"""
+AI Processor - Legacy Import Wrapper
+
+This file provides backward compatibility for code that imports from ai_processor.
+All functionality has been moved to the ai_processor/ module.
+
+Usage (new):
+    from ai_processor import analyze_scan_structure_with_ai
+
+Usage (legacy, still works):
+    from ai_processor import analyze_scan_structure_with_ai
+"""
+
+# Re-export everything from the new modular structure
+from ai_processor import (
+    # Configuration
+    BASE_DIR,
+    EINGANG_DIR,
+    BEREINIGT_DIR,
+    VISION_API,
+    # Utilities (with legacy aliases)
+    encode_image_to_data_url as _encode_image_to_data_url,
+    dummy_process_scan,
+    # Vision - Scan Analysis
+    analyze_scan_structure_with_ai,
+    describe_scan_with_ai,
+    remove_handwriting_from_scan,
+    build_clean_html_from_analysis,
+    # Generators - Multiple Choice
+    generate_mc_from_analysis,
+    # Generators - Cloze
+    generate_cloze_from_analysis,
+    # Generators - Q&A with Leitner
+    generate_qa_from_analysis,
+    update_leitner_progress,
+    get_next_review_items,
+    # Export - Print Versions
+    generate_print_version_qa,
+    generate_print_version_cloze,
+    generate_print_version_mc,
+    generate_print_version_worksheet,
+    # Visualization - Mindmap
+    generate_mindmap_data,
+    generate_mindmap_html,
+    save_mindmap_for_worksheet,
+)
+
+# Legacy function alias
+from ai_processor import get_openai_api_key as _get_api_key
+
+__all__ = [
+    # Configuration
+    "BASE_DIR",
+    "EINGANG_DIR",
+    "BEREINIGT_DIR",
+    "VISION_API",
+    # Legacy private functions
+    "_get_api_key",
+    "_encode_image_to_data_url",
+    # Vision
+    "analyze_scan_structure_with_ai",
+    "describe_scan_with_ai",
+    "remove_handwriting_from_scan",
+    "build_clean_html_from_analysis",
+    "dummy_process_scan",
+    # Generators
+    "generate_mc_from_analysis",
+    "generate_cloze_from_analysis",
+    "generate_qa_from_analysis",
+    "update_leitner_progress",
+    "get_next_review_items",
+    # Export
+    "generate_print_version_qa",
+    "generate_print_version_cloze",
+    "generate_print_version_mc",
+    "generate_print_version_worksheet",
+    # Visualization
+    "generate_mindmap_data",
+    "generate_mindmap_html",
+    "save_mindmap_for_worksheet",
+]