fix: enforce pause checks

[mk0walsk]

This PR makes bridge pause checks actually block execution.

Several bridge flows were calling isBridgePaused().then(...), which does not gate the current async flow and can throw outside local try/catch. That means paused-state checks could be bypassed in practice.
I replaced those call sites with awaited guards (if (await isBridgePaused()) ...) in the bridge/approval paths and used early returns in UI handlers where throwing would become an unhandled async error.

I also added explicit BridgePausedError handling in handleBridgeError, so paused-state failures show a clear paused message instead of falling back to a generic unknown error.