[split-required] Split 700-870 LOC files across all services

backend-lehrer (11 files):
- llm_gateway/routes/schools.py (867 → 5), recording_api.py (848 → 6)
- messenger_api.py (840 → 5), print_generator.py (824 → 5)
- unit_analytics_api.py (751 → 5), classroom/routes/context.py (726 → 4)
- llm_gateway/routes/edu_search_seeds.py (710 → 4)

klausur-service (12 files):
- ocr_labeling_api.py (845 → 4), metrics_db.py (833 → 4)
- legal_corpus_api.py (790 → 4), page_crop.py (758 → 3)
- mail/ai_service.py (747 → 4), github_crawler.py (767 → 3)
- trocr_service.py (730 → 4), full_compliance_pipeline.py (723 → 4)
- dsfa_rag_api.py (715 → 4), ocr_pipeline_auto.py (705 → 4)

website (6 pages):
- audit-checklist (867 → 8), content (806 → 6)
- screen-flow (790 → 4), scraper (789 → 5)
- zeugnisse (776 → 5), modules (745 → 4)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

backend-lehrer/recording_helpers.py

@@ -0,0 +1,57 @@
+"""
+Recording API - In-Memory Storage & Helpers.
+
+Shared state and utility functions for recording endpoints.
+"""
+
+import uuid
+from datetime import datetime
+from typing import Optional
+
+
+# ==========================================
+# IN-MEMORY STORAGE (Dev Mode)
+# ==========================================
+# In production, these would be database queries
+
+_recordings_store: dict = {}
+_transcriptions_store: dict = {}
+_audit_log: list = []
+_minutes_store: dict = {}
+
+
+def log_audit(
+    action: str,
+    recording_id: Optional[str] = None,
+    transcription_id: Optional[str] = None,
+    user_id: Optional[str] = None,
+    metadata: Optional[dict] = None
+):
+    """Log audit event for DSGVO compliance."""
+    _audit_log.append({
+        "id": str(uuid.uuid4()),
+        "recording_id": recording_id,
+        "transcription_id": transcription_id,
+        "user_id": user_id,
+        "action": action,
+        "metadata": metadata or {},
+        "created_at": datetime.utcnow().isoformat()
+    })
+
+
+def format_vtt_time(ms: int) -> str:
+    """Format milliseconds to VTT timestamp (HH:MM:SS.mmm)."""
+    hours = ms // 3600000
+    minutes = (ms % 3600000) // 60000
+    seconds = (ms % 60000) // 1000
+    millis = ms % 1000
+    return f"{hours:02d}:{minutes:02d}:{seconds:02d}.{millis:03d}"
+
+
+def format_srt_time(ms: int) -> str:
+    """Format milliseconds to SRT timestamp (HH:MM:SS,mmm)."""
+    hours = ms // 3600000
+    minutes = (ms % 3600000) // 60000
+    seconds = (ms % 60000) // 1000
+    millis = ms % 1000
+    return f"{hours:02d}:{minutes:02d}:{seconds:02d},{millis:03d}"