feat(system): enable window destroy capability and stabilize shutdown

Adds a new window capability to allow destroying the window.
It also changes shutdown handling in telemetry to avoid errors.

- Add core:window:allow-destroy to default capabilities
- Avoid shutdown errors by returning a pending promise in tracedInvoke
- Improve stability during shutdown for in-flight telemetry calls

src-tauri/capabilities/default.json

@@ -9,6 +9,7 @@
     "core:window:allow-toggle-maximize",
     "core:window:allow-unminimize",
     "core:window:allow-close",
+    "core:window:allow-destroy",
     "core:window:allow-is-maximized",
     "core:window:allow-start-dragging",
     "dialog:allow-open",