Introduce services/traefik_urls.go to centralize Traefik URL helpers and add opt-in fallback probing via TRAEFIK_API_FALLBACK_URLS. defaultTraefikURL now prefers TRAEFIK_API_URL before falling back to http://traefik:8080. main.go only auto-discovers the Traefik API when TRAEFIK_API_URL is empty and TRAEFIK_API_DISCOVER=true. Service fetchers were refactored to use fallbackTraefikURLsFromEnv (and return an error if no fallbacks are configured) and a noisy non-critical endpoint warning log was removed. These changes make fallback probing explicit and avoid silently overriding user-provided TRAEFIK_API_URL.
Bump Go versions in CI, Dockerfile and go.mod/toolchain to 1.25.x and update several module dependencies. Introduce rollbackTransaction(tx, context) and replace direct tx.Rollback() calls (including panic recovery) across handlers to centralize rollback logging/handling. Replace direct json.Unmarshal/Scan calls in tests with mustUnmarshalResponse/mustScan helpers. Add TrustedProxies to ServerConfig and configure Gin with SetTrustedProxies. Misc: adjust final Docker image (Alpine version and healthcheck command) and minor logging/formatting cleanups.
