Removed the Config Manager Integration block and all 19 backward-compat
variable re-exports (LLAMA_URL, CHESHIRE_CAT_URL, LANGUAGE_MODE, etc.)
from config.py. These were dead code because:
1. Circular import: config.py tried to import config_manager at module
level, but config_manager.py imports from config.py first, so
HAS_CONFIG_MANAGER was always False and _get_config_value() was a
no-op that always returned the static value.
2. Frozen snapshots: Even if the circular import worked, the values were
assigned to module-level names at import time and never updated. Other
modules importing 'from config import LLAMA_URL' would get a stale
snapshot, not a live value.
3. Nothing imports them: The entire codebase uses globals.py for mutable
runtime state, not these config.py copies. Only ERROR_WEBHOOK_URL was
imported (by error_handler.py), so it is kept as a simple re-export
from SECRETS.
Also cleaned up unused imports: Any, field_validator.
Japanese mode is NOT affected — LANGUAGE_MODE and JAPANESE_TEXT_MODEL live
in globals.py and are untouched.