[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/unit_analytics_export.py

@@ -0,0 +1,145 @@
+"""
+Unit Analytics API - Export & Dashboard Routes.
+
+Export endpoints for learning gains and misconceptions, plus dashboard overview.
+"""
+
+import logging
+from datetime import datetime
+from typing import Optional, Dict, Any
+
+from fastapi import APIRouter, Query
+from fastapi.responses import Response
+
+from unit_analytics_models import TimeRange, ExportFormat
+from unit_analytics_helpers import get_analytics_database
+
+logger = logging.getLogger(__name__)
+
+router = APIRouter(tags=["Unit Analytics"])
+
+
+# ==============================================
+# API Endpoints - Export
+# ==============================================
+
+@router.get("/export/learning-gains")
+async def export_learning_gains(
+    unit_id: Optional[str] = Query(None),
+    class_id: Optional[str] = Query(None),
+    time_range: TimeRange = Query(TimeRange.ALL),
+    format: ExportFormat = Query(ExportFormat.JSON),
+) -> Any:
+    """
+    Export learning gain data.
+    """
+    db = await get_analytics_database()
+    data = []
+
+    if db:
+        try:
+            data = await db.export_learning_gains(
+                unit_id=unit_id, class_id=class_id, time_range=time_range.value
+            )
+        except Exception as e:
+            logger.error(f"Failed to export data: {e}")
+
+    if format == ExportFormat.CSV:
+        if not data:
+            csv_content = "student_id,unit_id,precheck,postcheck,gain\n"
+        else:
+            csv_content = "student_id,unit_id,precheck,postcheck,gain\n"
+            for row in data:
+                csv_content += f"{row['student_id']},{row['unit_id']},{row.get('precheck', '')},{row.get('postcheck', '')},{row.get('gain', '')}\n"
+
+        return Response(
+            content=csv_content,
+            media_type="text/csv",
+            headers={"Content-Disposition": "attachment; filename=learning_gains.csv"}
+        )
+
+    return {
+        "export_date": datetime.utcnow().isoformat(),
+        "filters": {
+            "unit_id": unit_id, "class_id": class_id, "time_range": time_range.value,
+        },
+        "data": data,
+    }
+
+
+@router.get("/export/misconceptions")
+async def export_misconceptions(
+    class_id: Optional[str] = Query(None),
+    format: ExportFormat = Query(ExportFormat.JSON),
+) -> Any:
+    """
+    Export misconception data for further analysis.
+    """
+    # Import here to avoid circular dependency
+    from unit_analytics_routes import get_misconception_report
+
+    report = await get_misconception_report(
+        class_id=class_id, unit_id=None,
+        time_range=TimeRange.MONTH, limit=100
+    )
+
+    if format == ExportFormat.CSV:
+        csv_content = "concept_id,concept_label,misconception,frequency,unit_id,stop_id\n"
+        for m in report.most_common:
+            csv_content += f'"{m.concept_id}","{m.concept_label}","{m.misconception_text}",{m.frequency},"{m.unit_id}","{m.stop_id}"\n'
+
+        return Response(
+            content=csv_content,
+            media_type="text/csv",
+            headers={"Content-Disposition": "attachment; filename=misconceptions.csv"}
+        )
+
+    return {
+        "export_date": datetime.utcnow().isoformat(),
+        "class_id": class_id,
+        "total_entries": len(report.most_common),
+        "data": [m.model_dump() for m in report.most_common],
+    }
+
+
+# ==============================================
+# API Endpoints - Dashboard Aggregates
+# ==============================================
+
+@router.get("/dashboard/overview")
+async def get_analytics_overview(
+    time_range: TimeRange = Query(TimeRange.MONTH),
+) -> Dict[str, Any]:
+    """
+    Get high-level analytics overview for dashboard.
+    """
+    db = await get_analytics_database()
+
+    if db:
+        try:
+            overview = await db.get_analytics_overview(time_range.value)
+            return overview
+        except Exception as e:
+            logger.error(f"Failed to get analytics overview: {e}")
+
+    return {
+        "time_range": time_range.value,
+        "total_sessions": 0,
+        "unique_students": 0,
+        "avg_completion_rate": 0.0,
+        "avg_learning_gain": 0.0,
+        "most_played_units": [],
+        "struggling_concepts": [],
+        "active_classes": 0,
+    }
+
+
+@router.get("/health")
+async def health_check() -> Dict[str, Any]:
+    """Health check for analytics API."""
+    db = await get_analytics_database()
+    return {
+        "status": "healthy",
+        "service": "unit-analytics",
+        "database": "connected" if db else "disconnected",
+    }