fix(bindings): atomically replace persisted store

[xuyua9]

Summary

Make persisted binding updates resilient to interruption while preserving the existing bindings.json contents until the replacement is ready.

Changes

• Serialize to a uniquely named file beside bindings.json.
• Write the complete payload and call sync_all() before replacement.
• Use an atomic same-directory rename on Unix-like systems.
• Use Windows MoveFileExW with REPLACE_EXISTING | WRITE_THROUGH so replacing an existing file does not fail on Windows.
• Clean up the temporary file when preparation or replacement fails.
• Add a regression test for replacing and reloading persisted bindings.

Verification

• cargo fmt --check
• cargo test -p desk_remote_core -- --test-threads=1 (10 passed)
• cargo check --workspace

The Windows-specific code was statically included behind cfg(windows); this environment does not have a Windows runtime target, so no Windows runtime test is claimed.

[vercel]

@xuyua9 is attempting to deploy a commit to the postigodev's projects Team on Vercel.

A member of the Team first needs to authorize it.