Add optional HTTPS support controlled by two env vars:
HERMES_WEBUI_TLS_CERT=/path/to/cert.pem
HERMES_WEBUI_TLS_KEY=/path/to/key.pem
- Wraps server socket with ssl.SSLContext (min TLSv1.2)
- Dynamic scheme detection for startup messages (http:// vs https://)
- Graceful fallback to HTTP if cert loading fails — server never crashes
due to bad TLS config, just prints a warning and continues
- Auth cookie Secure flag already set when HTTPS is detected via getpeercert
- 6 end-to-end tests: config flags, HTTPS handshake, HTTP still works,
fallback on bad paths
Addresses #191 (HTTPS support issue).
