feat: migrate to Poetry and implement multi-backend DNS management ✨

- Migrated from setuptools to Poetry; added pyproject.toml, poetry.lock,
  poetry.toml and .python-version (Python 3.11.12)
- Built out full directdnsonly Python package with BIND and CoreDNS MySQL
  backends, CherryPy REST API, persist-queue worker, and vyper-based config
- Auth credentials now read from config/env (app.auth_username/password)
  rather than hardcoded; override via DADNS_APP_AUTH_PASSWORD env var
- Added Dockerfile.deepseek: Python 3.11 slim + BIND9 + Poetry install
- Rewrote docker-compose.yml for local dev stack (MySQL + dadns services)
- Added SQL schema, docker/ BIND configs, justfile, tests, and README
- Expanded .gitignore for Poetry/Python project artifacts

justfile

@@ -0,0 +1,17 @@
+#!/usr/bin/env just --justfile
+APP_NAME := "directdnsonly"
+build:
+    cd src && \
+    pyinstaller \
+    -p . \
+    --hidden-import=json \
+    --hidden-import=pyopenssl \
+    --hidden-import=pymysql \
+    --hidden-import=jaraco \
+    --hidden-import=cheroot \
+    --hidden-import=cheroot.ssl.pyopenssl \
+    --hidden-import=cheroot.ssl.builtin \
+    --hidden-import=lib \
+    --hidden-import=os \
+    --hidden-import=builtins \
+    --noconfirm --onefile {{APP_NAME}}.py