CVE-2026-55677: stop unescaping the static file wildcard by default in
Static, StaticFS, Group.StaticFS and StaticWithConfig of the vendored
github.com/labstack/echo/v4 (the echo v4.15.4 fix), so an encoded
separator (%2F, %5C) or dot-segment (%2E%2E) cannot resolve a static
file outside the route the router matched and bypass route-level
middleware; unescaping is opt-in via EnablePathUnescapingStaticFiles
and StaticConfig.EnablePathUnescaping