Preserve backup_old_docker bot variant at root (for comparison)

Snapshot of the dockerisation-era bot code laid out at the repository
root so it can be diffed directly against the working-copy baseline
(restructure/working-copy-root) to see how the variant differed:

- thin_client.py asyncio entrypoint (vs working_copy bot.py)
- constants.py env-var/credential refactor, communication auth, etc.
- extra gpt_interface/ service, sync.py, watch_script_params.py
- conanjurer_* modules absent in this variant

Docker infrastructure (docker/, docker-compose.yml, .dockerignore)
intentionally omitted - this branch is for code comparison only and is
not intended to be merged.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

latex_commands.py

@@ -10,7 +10,7 @@ import discord
 from discord import app_commands
 from discord.ext import commands
 
-from constants import (
+from conjurer.backup_old_docker.constants import (
     ALLOWED_ROLES,
     GUILD_ID,
     LATEX_MAX_ATTACH_MB,
@@ -19,7 +19,7 @@ from constants import (
     LATEX_TEX_ENGINE,
     OPENAI_MODEL,
 )
-from latex_functions import (
+from conjurer.backup_old_docker.latex_functions import (
     compile_single_tex_bytes,
     compile_zip_to_zip,
     is_safe_asset_name,