refactor(bridge): drop now-unused imports from the facade (stage 3 cleanup)

After extracting everything into modules/mixins, several stdlib imports in
kobrax_moonraker_bridge.py (sqlite3, uuid, hashlib, tempfile, subprocess,
pathlib, html, urllib.parse.quote) are no longer referenced there - they
travelled with GCodeStore/credentials/camera/endpoints. Removed.

Facade is now 1315 lines (down from 6368). All 184 tests green; live-verified
against a real printer that every mixin's endpoints resolve and serve
correctly (kobra_state, AMS slots flowing end to end). PyInstaller spec needs
no change - all 12 new modules are statically importable from the facade.

kobrax_moonraker_bridge.py

@@ -26,27 +26,19 @@ This project is not affiliated with Anycubic. See NOTICE.md for details.
 """
 
 import argparse
-import sqlite3
-import uuid
 try:
     import config_loader as env_loader
 except ImportError:
     import env_loader
 import asyncio
-import hashlib
 import copy
 import json
 import logging
 import os
-import pathlib
 import re
-import subprocess
 import sys
-import tempfile
 import time
 import threading
-import html
-from urllib.parse import quote
 
 # For PyInstaller binaries everything sits next to sys.executable, otherwise next to __file__
 _BASE = os.path.dirname(sys.executable) if getattr(sys, "frozen", False) else os.path.dirname(os.path.abspath(__file__))