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

.env.example

@@ -0,0 +1,26 @@
+# Runtime data — generated by deploy.sh, consumed by app.py
+# Copy this file to .env and adjust as needed, or export the vars before starting.
+
+# Flask session secret — MUST be changed in production!
+# Generate with: python3 -c "import secrets; print(secrets.token_urlsafe(48))"
+SECRET_KEY=change-me-in-production
+
+# Bind address / port (gunicorn)
+SQUIDMGR_HOST=0.0.0.0
+SQUIDMGR_PORT=5200
+SQUIDMGR_WORKERS=2
+SQUIDMGR_TIMEOUT=120
+
+# Squid paths (override if squid is in a non-standard location)
+# SQUID_BINARY=squid
+# SQUID_CONF=/etc/squid/squid.conf
+# SQUID_ACCESS_LOG=/var/log/squid/access.log
+# SQUID_CACHE_LOG=/var/log/squid/cache.log
+
+# Session / security
+SQUIDMGR_IDLE_TO=1800
+SQUIDMGR_ABS_TO=28800
+SQUIDMGR_THROTTLE_WIN=300
+SQUIDMGR_THROTTLE_MAX=5
+SQUIDMGR_THROTTLE_LOCK=900
+SQUIDMGR_CSRF=1