Function resolve 

pub fn resolve<'a>(
    routes: &'a [RouteDef],
    action: &str,
    params: &Params,
    mode: ControllerMode,
) -> Result<(&'a RouteDef, ExtractedParams), WebError>

Main route resolution function. Tries each route in declaration order and returns the first whose path pattern and verb both match, along with its extracted parameters.

“Declaration order” matters: when two patterns can match the same action (e.g. "special" and "{id}"), the one declared first wins — list the more specific route earlier.

When no route fully matches, the error distinguishes:

• WebError::MethodNotAllowed(methods): at least one route’s path pattern matched but its verb didn’t; methods is the (sorted, deduped) set of verbs those routes accept, which the caller surfaces as the Allow header.
• WebError::NotFound: no route’s path pattern matched at all.