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>

klausur-service/backend/models/requests.py

@@ -0,0 +1,152 @@
+"""
+Klausur-Service Request Models
+
+Pydantic models for API request/response validation.
+"""
+
+from typing import Optional, List, Dict, Any
+from pydantic import BaseModel
+
+from .enums import KlausurModus
+
+
+# =============================================
+# KLAUSUR REQUESTS
+# =============================================
+
+class KlausurCreate(BaseModel):
+    """Request to create a new Klausur."""
+    title: str
+    subject: str
+    modus: KlausurModus = KlausurModus.VORABITUR
+    class_id: Optional[str] = None
+    year: int = 2025
+    semester: str = "Q1"
+
+
+class KlausurUpdate(BaseModel):
+    """Request to update a Klausur."""
+    title: Optional[str] = None
+    subject: Optional[str] = None
+    erwartungshorizont: Optional[Dict[str, Any]] = None
+
+
+# =============================================
+# STUDENT REQUESTS
+# =============================================
+
+class StudentUpload(BaseModel):
+    """Request for student work upload metadata."""
+    student_name: str
+    student_id: Optional[str] = None
+
+
+# =============================================
+# GRADING REQUESTS
+# =============================================
+
+class CriterionScoreUpdate(BaseModel):
+    """Request to update a criterion score."""
+    criterion: str
+    score: int
+    annotations: Optional[List[str]] = None
+
+
+class GutachtenUpdate(BaseModel):
+    """Request to update the Gutachten."""
+    einleitung: str
+    hauptteil: str
+    fazit: str
+    staerken: Optional[List[str]] = None
+    schwaechen: Optional[List[str]] = None
+
+
+class GutachtenGenerateRequest(BaseModel):
+    """Request to generate a KI-based Gutachten."""
+    include_strengths: bool = True
+    include_weaknesses: bool = True
+    tone: str = "formal"  # formal, friendly, constructive
+    # BYOEH RAG Integration
+    use_eh: bool = False  # Whether to use Erwartungshorizont for context
+    eh_passphrase: Optional[str] = None  # Passphrase for EH decryption
+
+
+# =============================================
+# EXAMINER REQUESTS
+# =============================================
+
+class ExaminerAssignment(BaseModel):
+    """Request to assign an examiner."""
+    examiner_id: str
+    examiner_role: str  # first_examiner, second_examiner
+    notes: Optional[str] = None
+
+
+class ExaminerResult(BaseModel):
+    """Request to submit an examiner's result."""
+    grade_points: int
+    notes: Optional[str] = None
+
+
+# =============================================
+# BYOEH REQUESTS
+# =============================================
+
+class EHMetadata(BaseModel):
+    """Metadata for an Erwartungshorizont."""
+    title: str
+    subject: str
+    niveau: str  # 'eA' | 'gA'
+    year: int
+    aufgaben_nummer: Optional[str] = None
+
+
+class EHUploadMetadata(BaseModel):
+    """Metadata for EH upload including encryption info."""
+    metadata: EHMetadata
+    encryption_key_hash: str
+    salt: str
+    rights_confirmed: bool
+    original_filename: str
+
+
+class EHRAGQuery(BaseModel):
+    """Request for RAG query against Erwartungshorizonte."""
+    query_text: str
+    passphrase: str
+    subject: Optional[str] = None
+    limit: int = 5
+
+
+class EHIndexRequest(BaseModel):
+    """Request to index an Erwartungshorizont."""
+    passphrase: str
+
+
+class EHShareRequest(BaseModel):
+    """Request to share EH with another examiner."""
+    user_id: str  # User to share with
+    role: str  # second_examiner, third_examiner, supervisor
+    encrypted_passphrase: str  # Passphrase encrypted for recipient
+    passphrase_hint: Optional[str] = None
+    klausur_id: Optional[str] = None  # Optional: link to specific Klausur
+
+
+class EHLinkKlausurRequest(BaseModel):
+    """Request to link EH to a Klausur."""
+    klausur_id: str
+
+
+class EHInviteRequest(BaseModel):
+    """Request to invite another user to access an EH."""
+    invitee_email: str  # Email of the recipient
+    invitee_id: Optional[str] = None  # User ID if known
+    role: str  # second_examiner, third_examiner, supervisor, department_head
+    klausur_id: Optional[str] = None  # Optional: link to specific Klausur
+    message: Optional[str] = None  # Optional message for the invitee
+    expires_in_days: int = 14  # Default 14 days expiration
+
+
+class EHAcceptInviteRequest(BaseModel):
+    """Request to accept an invitation and receive the encrypted passphrase."""
+    encrypted_passphrase: str  # The passphrase encrypted for the invitee