Docker HTTPS by default, smoke test improvements

Docker:
- HTTPS enabled by default (generates self-signed cert)
- Added docker-entrypoint.sh for SSL cert generation
- Gunicorn now starts with --certfile/--keyfile when HTTPS enabled
- Install curl/openssl in web container for healthcheck and certs
- Updated docs to reflect HTTPS default

Smoke Test:
- Moved from rpi/ to scripts/ (works for Pi, Docker, and dev)
- Updated header and examples
- Added to .gitignore exceptions

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

DOCKER.md

@@ -13,7 +13,7 @@ docker-compose ps
 ```
 
 Access:
-- **Web UI**: http://localhost:5000
+- **Web UI**: https://localhost:5000 (HTTPS with self-signed cert)
 - **REST API**: http://localhost:8000
 
 ## Services
@@ -36,9 +36,12 @@ STEGASOO_CHANNEL_KEY=XXXX-XXXX-XXXX-XXXX-XXXX-XXXX-XXXX-XXXX
 # Web UI authentication (default: enabled)
 STEGASOO_AUTH_ENABLED=true
 
-# HTTPS support (default: disabled)
-STEGASOO_HTTPS_ENABLED=false
+# HTTPS support (default: enabled, generates self-signed cert)
+STEGASOO_HTTPS_ENABLED=true
 STEGASOO_HOSTNAME=localhost
+
+# To disable HTTPS:
+# STEGASOO_HTTPS_ENABLED=false
 ```
 
 ### Volume Mounts