Improve overall code structure and maintainability

[Copilot]

This PR improves the overall code structure of the CFMS WebSocket server project by addressing several code quality and maintainability issues without changing any functionality.

Changes Overview

Package Structure

Added __init__.py files to all Python package directories to properly define the package hierarchy. Each file includes descriptive docstrings explaining the package's purpose:

• include/ - Core functionality package
• include/classes/ - Connection, request, and auth classes
• include/database/ and include/database/models/ - Database ORM models
• include/handlers/ and include/handlers/management/ - Request handlers
• include/util/ and include/util/rule/ - Utility functions
• include/system/ - System-level messages

Import Organization (PEP 8 Compliance)

Refactored imports across the codebase to follow PEP 8 guidelines:

• Fixed combined imports (e.g., import os, sys → separate lines)
• Organized imports into logical groups: standard library, third-party, local modules
• Removed unused imports (e.g., MetaData from database handler)

Files updated: conf_loader.py, test.py, auth.py, file.py, user.py, main.py, connection.py, database/handler.py, document.py

Constants and Magic Numbers

Extracted hardcoded values into named constants for better maintainability:

# Before
time.sleep(3)
token.new(3600)
datetime.timedelta(days=365)

# After
time.sleep(FAILED_LOGIN_DELAY_SECONDS)
token.new(DEFAULT_TOKEN_EXPIRY_SECONDS)
datetime.timedelta(days=DEFAULT_SSL_CERT_VALIDITY_DAYS)

New constants added:

• DEFAULT_TOKEN_EXPIRY_SECONDS = 3600 (1 hour)
• FAILED_LOGIN_DELAY_SECONDS = 3 (security delay after failed login)
• DEFAULT_SSL_CERT_VALIDITY_DAYS = 365 (certificate validity period)
• FILE_TRANSFER_CHUNK_SIZE = 8192 (8KB threshold for file transfers)
• FILE_TASK_DEFAULT_DURATION_SECONDS = 3600 (task duration)

Also added comprehensive __all__ list to constants.py for explicit public API exports.

Type Hints and Code Quality

Enhanced type safety and fixed Python antipatterns:

Mutable default arguments fixed:

# Before - dangerous mutable default
def conclude_request(self, code: int, data: dict = {}, message: str = ""):

# After - safe immutable default
def conclude_request(self, code: int, data: Optional[dict] = None, message: str = ""):
    response = {
        "data": data if data is not None else {},
        ...
    }

Type hints added:

• getCustomLogger() -> logging.Logger
• log_audit() -> None
• check_passwd_requirements() -> None
• Added Optional type hints for nullable parameters

Code Cleanup

Removed dead code and improved documentation:

• Removed commented-out authenticate_user() method
• Cleaned up old function signatures and commented imports
• Removed unused metadata code in database models
• Enhanced docstring quality and consistency

Testing & Verification

• ✅ All Python files compile successfully
• ✅ Automated code review: No issues found
• ✅ CodeQL security scan: 0 alerts
• ✅ No functional changes, only structural improvements

Impact

These changes improve code maintainability, readability, and adherence to Python best practices without affecting any existing functionality. The codebase is now better structured for future development and easier to understand for new contributors.

Original prompt

Improve overall code structures

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[Creeper19472]

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