Fix Pyright type errors and remove unused imports

- audit_trail.py: Add None guard for self.log_path before os.path.abspath()
  and open() calls; remove unused imports (time, asdict, field, Path)
- cui_detector.py: Remove unused imports (Dict, Set, Tuple); remove unused
  `lines` variable in _check_marking_compliance
- enhanced_pii.py: Remove unused imports (field, Optional)
- sanitizer.py: Remove unused imports (json, struct, field, BinaryIO, Tuple)
- export_control.py: Remove unused import (field)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: marc-shade

docsingest/compliance/audit_trail.py

@@ -17,12 +17,10 @@
 import logging
 import os
 import socket
-import time
 import uuid
-from dataclasses import asdict, dataclass, field
+from dataclasses import dataclass
 from datetime import datetime, timezone
 from enum import Enum
-from pathlib import Path
 from typing import Any, Dict, List, Optional
 
 logger = logging.getLogger(__name__)
@@ -615,6 +613,8 @@ def _get_local_ip() -> str:
     def _append_to_log(self, entry: AuditEntry) -> None:
         """Append an entry to the audit log file."""
         try:
+            if self.log_path is None:
+                raise ValueError("log_path is required for file operations")
             os.makedirs(os.path.dirname(os.path.abspath(self.log_path)), exist_ok=True)
             with open(self.log_path, 'a', encoding='utf-8') as f:
                 f.write(json.dumps(entry.to_dict(), separators=(',', ':')) + '\n')

docsingest/compliance/cui_detector.py

@@ -15,7 +15,7 @@
 import re
 from dataclasses import dataclass, field
 from enum import Enum
-from typing import Dict, List, Optional, Set, Tuple
+from typing import List, Optional
 
 logger = logging.getLogger(__name__)
 
@@ -443,7 +443,6 @@ def _check_marking_compliance(
         Returns list of deficiency descriptions.
         """
         deficiencies: List[str] = []
-        lines = text.split('\n')
 
         # Check 1: CUI content without proper header banner
         if cui_markings and not any(b.position_in_document == "header" for b in banners):

docsingest/compliance/enhanced_pii.py

@@ -20,9 +20,9 @@
 
 import logging
 import re
-from dataclasses import dataclass, field
+from dataclasses import dataclass
 from enum import Enum
-from typing import Dict, List, Optional, Tuple
+from typing import Dict, List, Tuple
 
 logger = logging.getLogger(__name__)
 

docsingest/compliance/export_control.py

@@ -19,7 +19,7 @@
 
 import logging
 import re
-from dataclasses import dataclass, field
+from dataclasses import dataclass
 from enum import Enum
 from typing import Dict, List, Optional, Set, Tuple
 

docsingest/compliance/sanitizer.py

@@ -18,15 +18,13 @@
 """
 
 import hashlib
-import json
 import logging
 import os
 import re
-import struct
 import zipfile
-from dataclasses import dataclass, field
+from dataclasses import dataclass
 from enum import Enum
-from typing import Any, BinaryIO, Dict, List, Optional, Set, Tuple
+from typing import Any, Dict, List, Optional, Set
 
 logger = logging.getLogger(__name__)