fix(macos): clamp oversized initial window size

[justjavac]

What changed

Clamp oversized macOS initial inner window dimensions before constructing the native NSWindow.

Refs tauri-apps/tauri#15648.
Follow-up for tauri-apps/tauri#15649.

Validation

• cargo fmt --check (passes; prints existing imports_granularity nightly warnings)
• cargo test initial_inner_size --lib
• cargo test --lib
• cargo check (passes with existing warnings)
• git diff --check

Tauri-side reproduction before moving this upstream: setting the helloworld example width to 2147483648 aborted during macOS did_finish_launching; applying the same clamp before native window creation allowed the app to enter the event loop.