Fix code formatting and linting issues

- Auto-format all Python files with black and isort
- Remove unused imports with autoflake
- Fix flake8 issues (missing newlines, blank lines, etc.)
- Fix nonlocal/global scope issues in main.py
- Fix security.py import order (E402)
- Remove f-string without placeholders
- Add nosec comment for intentional exception handling
- Fix test imports to match refactored DMARCParser API

Co-authored-by: christianlouis <361235+christianlouis@users.noreply.github.com>

backend/app/models/domain.py

@@ -1,68 +1,66 @@
-from typing import List, Optional
 from datetime import datetime
 
-from sqlalchemy import Boolean, Column, DateTime, ForeignKey, Integer, String, Text, Index
-from sqlalchemy.orm import relationship
-
 from app.core.database import Base
+from sqlalchemy import Boolean, Column, DateTime, ForeignKey, Index, Integer, String, Text
+from sqlalchemy.orm import relationship
 
 
 class Domain(Base):
     """Domain model representing a monitored domain"""
-    
+
     __tablename__ = "domains"
-    
+
     id = Column(Integer, primary_key=True, index=True)
     name = Column(String, unique=True, index=True, nullable=False)
     description = Column(Text, nullable=True)
     active = Column(Boolean, default=True, index=True)
-    
+
     # DMARC policy information
     dmarc_policy = Column(String, nullable=True, index=True)
     spf_record = Column(String, nullable=True)
     dkim_selectors = Column(String, nullable=True)  # Comma-separated list of DKIM selectors
-    
+
     # DNS verification status
     verified = Column(Boolean, default=False, index=True)
     verification_token = Column(String, nullable=True)
-    
+
     # Date fields
     created_at = Column(DateTime, default=datetime.utcnow, index=True)
     updated_at = Column(DateTime, default=datetime.utcnow, onupdate=datetime.utcnow)
-    
+
     # Relationships
     reports = relationship("DMARCReport", back_populates="domain", cascade="all, delete-orphan")
     user_domains = relationship("UserDomain", back_populates="domain", cascade="all, delete-orphan")
-    
+
     # Indexes for common queries
     __table_args__ = (
         # Index for finding active and verified domains
-        Index('ix_domains_active_verified', 'active', 'verified'),
+        Index("ix_domains_active_verified", "active", "verified"),
         # Index for finding domains by policy
-        Index('ix_domains_policy', 'dmarc_policy'),
+        Index("ix_domains_policy", "dmarc_policy"),
         # Index for finding recently updated domains
-        Index('ix_domains_updated', 'updated_at'),
+        Index("ix_domains_updated", "updated_at"),
     )
-    
+
     def __repr__(self):
         return f"<Domain {self.name}>"
 
 
 class UserDomain(Base):
     """Association table for users and domains"""
-    
+
     __tablename__ = "user_domains"
-    
+
     id = Column(Integer, primary_key=True, index=True)
     user_id = Column(Integer, ForeignKey("users.id"), nullable=False)
     domain_id = Column(Integer, ForeignKey("domains.id"), nullable=False)
-    
+
     # Access level (admin, viewer, etc)
     role = Column(String, default="viewer", nullable=False)
-    
+
     # Date fields
     created_at = Column(DateTime, default=datetime.utcnow)
-    
+
     # Relationships
     user = relationship("User", back_populates="user_domains")
-    domain = relationship("Domain", back_populates="user_domains")
+    domain = relationship("Domain", back_populates="user_domains")