feat: add one-click deploy script + project optimization

- deploy.sh: one-click deployment (squid + venv + pip + gunicorn + systemd)
- gunicorn_config.py: unified gunicorn config with env var overrides
- .env.example: env var template for SECRET_KEY, port, workers, security
- wsgi.py: create all runtime dirs (uploads, ssl_certs); optional dotenv loading
- requirements.txt: add python-dotenv + cryptography
- .gitignore: cover runtime dirs, .env, pyc files

gunicorn_config.py

@@ -0,0 +1,34 @@
+"""Gunicorn configuration for Squid Manager.
+
+Usage:
+    gunicorn -c gunicorn_config.py wsgi:app
+
+All values can be overridden via environment variables:
+    SQUIDMGR_HOST        bind address  (default: 0.0.0.0)
+    SQUIDMGR_PORT        bind port     (default: 5200)
+    SQUIDMGR_WORKERS     worker count  (default: 2)
+    SQUIDMGR_TIMEOUT     worker timeout (default: 120)
+"""
+import multiprocessing
+import os
+
+_host = os.environ.get("SQUIDMGR_HOST", "0.0.0.0")
+_port = os.environ.get("SQUIDMGR_PORT", "5200")
+_workers = int(os.environ.get("SQUIDMGR_WORKERS", 2))
+_timeout = int(os.environ.get("SQUIDMGR_TIMEOUT", 120))
+
+bind = f"{_host}:{_port}"
+workers = _workers
+timeout = _timeout
+worker_class = "sync"
+
+# Logging
+accesslog = "-"      # stdout → journald
+errorlog = "-"       # stderr → journald
+loglevel = "info"
+
+# Preload app to share memory & fail fast on import errors
+preload_app = True
+
+# PID file (for health-check scripts)
+pidfile = os.path.join(os.path.dirname(os.path.abspath(__file__)), "instance", "gunicorn.pid")