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/alerts_agent/actions/base.py

@@ -0,0 +1,123 @@
+"""
+Base Classes für Alert Actions.
+
+Definiert das Interface für alle Action-Handler.
+"""
+from abc import ABC, abstractmethod
+from dataclasses import dataclass, field
+from datetime import datetime
+from typing import Dict, Any, Optional, List
+from enum import Enum
+
+
+class ActionType(str, Enum):
+    """Verfügbare Aktionstypen."""
+    EMAIL = "email"
+    WEBHOOK = "webhook"
+    SLACK = "slack"
+    TEAMS = "teams"
+    TAG = "tag"
+    ARCHIVE = "archive"
+
+
+@dataclass
+class ActionResult:
+    """Ergebnis einer ausgeführten Aktion."""
+    success: bool
+    action_type: ActionType
+    message: str
+    timestamp: datetime = field(default_factory=datetime.utcnow)
+    details: Dict[str, Any] = field(default_factory=dict)
+    error: Optional[str] = None
+
+    def to_dict(self) -> Dict[str, Any]:
+        """Konvertiert zu Dict für Logging/Speicherung."""
+        return {
+            "success": self.success,
+            "action_type": self.action_type.value,
+            "message": self.message,
+            "timestamp": self.timestamp.isoformat(),
+            "details": self.details,
+            "error": self.error,
+        }
+
+
+@dataclass
+class AlertContext:
+    """Kontext für eine Aktion mit Alert-Informationen."""
+    alert_id: str
+    title: str
+    url: str
+    snippet: str
+    topic_name: str
+    relevance_score: Optional[float] = None
+    relevance_decision: Optional[str] = None
+    matched_rule: Optional[str] = None
+    tags: List[str] = field(default_factory=list)
+
+    def to_dict(self) -> Dict[str, Any]:
+        """Konvertiert zu Dict für Templates."""
+        return {
+            "alert_id": self.alert_id,
+            "title": self.title,
+            "url": self.url,
+            "snippet": self.snippet,
+            "topic_name": self.topic_name,
+            "relevance_score": self.relevance_score,
+            "relevance_decision": self.relevance_decision,
+            "matched_rule": self.matched_rule,
+            "tags": self.tags,
+        }
+
+
+class ActionHandler(ABC):
+    """
+    Abstrakte Basisklasse für Action-Handler.
+
+    Jede Aktion (Email, Webhook, Slack) implementiert diese Schnittstelle.
+    """
+
+    @property
+    @abstractmethod
+    def action_type(self) -> ActionType:
+        """Gibt den Aktionstyp zurück."""
+        pass
+
+    @abstractmethod
+    async def execute(
+        self,
+        context: AlertContext,
+        config: Dict[str, Any],
+    ) -> ActionResult:
+        """
+        Führt die Aktion aus.
+
+        Args:
+            context: Alert-Kontext mit allen relevanten Informationen
+            config: Aktionsspezifische Konfiguration
+
+        Returns:
+            ActionResult mit Erfolgsstatus und Details
+        """
+        pass
+
+    def validate_config(self, config: Dict[str, Any]) -> bool:
+        """
+        Validiert die Aktions-Konfiguration.
+
+        Args:
+            config: Zu validierende Konfiguration
+
+        Returns:
+            True wenn gültig
+        """
+        return True
+
+    def get_required_config_fields(self) -> List[str]:
+        """
+        Gibt erforderliche Konfigurationsfelder zurück.
+
+        Returns:
+            Liste von Feldnamen
+        """
+        return []