[split-required] Split 500-1000 LOC files across all services

backend-lehrer (5 files):
- alerts_agent/db/repository.py (992 → 5), abitur_docs_api.py (956 → 3)
- teacher_dashboard_api.py (951 → 3), services/pdf_service.py (916 → 3)
- mail/mail_db.py (987 → 6)

klausur-service (5 files):
- legal_templates_ingestion.py (942 → 3), ocr_pipeline_postprocess.py (929 → 4)
- ocr_pipeline_words.py (876 → 3), ocr_pipeline_ocr_merge.py (616 → 2)
- KorrekturPage.tsx (956 → 6)

website (5 pages):
- mail (985 → 9), edu-search (958 → 8), mac-mini (950 → 7)
- ocr-labeling (946 → 7), audit-workspace (871 → 4)

studio-v2 (5 files + 1 deleted):
- page.tsx (946 → 5), MessagesContext.tsx (925 → 4)
- korrektur (914 → 6), worksheet-cleanup (899 → 6)
- useVocabWorksheet.ts (888 → 3)
- Deleted dead page-original.tsx (934 LOC)

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

backend-lehrer/services/pdf_models.py

@@ -0,0 +1,84 @@
+"""
+PDF Service - Data Models and Shared Types.
+
+Dataclasses for letters, certificates, and corrections.
+"""
+
+from dataclasses import dataclass
+from typing import Any, Dict, Optional, List
+
+
+@dataclass
+class SchoolInfo:
+    """Schulinformationen für Header."""
+    name: str
+    address: str
+    phone: str
+    email: str
+    logo_path: Optional[str] = None
+    website: Optional[str] = None
+    principal: Optional[str] = None
+
+
+@dataclass
+class LetterData:
+    """Daten für Elternbrief-PDF."""
+    recipient_name: str
+    recipient_address: str
+    student_name: str
+    student_class: str
+    subject: str
+    content: str
+    date: str
+    teacher_name: str
+    teacher_title: Optional[str] = None
+    school_info: Optional[SchoolInfo] = None
+    letter_type: str = "general"  # general, halbjahr, fehlzeiten, elternabend, lob
+    tone: str = "professional"
+    legal_references: Optional[List[Dict[str, str]]] = None
+    gfk_principles_applied: Optional[List[str]] = None
+
+
+@dataclass
+class CertificateData:
+    """Daten für Zeugnis-PDF."""
+    student_name: str
+    student_birthdate: str
+    student_class: str
+    school_year: str
+    certificate_type: str  # halbjahr, jahres, abschluss
+    subjects: List[Dict[str, Any]]  # [{name, grade, note}]
+    attendance: Dict[str, int]  # {days_absent, days_excused, days_unexcused}
+    remarks: Optional[str] = None
+    class_teacher: str = ""
+    principal: str = ""
+    school_info: Optional[SchoolInfo] = None
+    issue_date: str = ""
+    social_behavior: Optional[str] = None  # A, B, C, D
+    work_behavior: Optional[str] = None  # A, B, C, D
+
+
+@dataclass
+class StudentInfo:
+    """Schülerinformationen für Korrektur-PDFs."""
+    student_id: str
+    name: str
+    class_name: str
+
+
+@dataclass
+class CorrectionData:
+    """Daten für Korrektur-Übersicht PDF."""
+    student: StudentInfo
+    exam_title: str
+    subject: str
+    date: str
+    max_points: int
+    achieved_points: int
+    grade: str
+    percentage: float
+    corrections: List[Dict[str, Any]]  # [{question, answer, points, feedback}]
+    teacher_notes: str = ""
+    ai_feedback: str = ""
+    grade_distribution: Optional[Dict[str, int]] = None  # {note: anzahl}
+    class_average: Optional[float] = None