feat: implement Windows support for connectivity detection (#3)

[gabref]

Adds Windows support for connection_status() in tauri-plugin-connectivity.

• implement the Windows backend using WinRT NetworkInformation
• map connectivity, metered, constrained, and transport status into the existing plugin types
• include BackgroundDataUsageRestricted in the Windows constrained check
• split platform handling into per-platform modules
• add structured tracing logs for plugin setup, command handling, and Windows status resolution
• update docs to reflect Windows support
• add a small examples/tauri-app app for manual testing

Closes #3

[velocitysystems]

Instead of checking for a magic number 0, we should be able to use is_ok() on the HRESULT returned by error.code().

Then our usage becomes:

Err(error) if error.code().is_ok() => { ... }  

[gabref]

Thanks, I updated this. I checked our current windows crate version and error.code().is_ok() is supported there, and it handles the Error::empty() / no-profile case we get from GetInternetConnectionProfile(). I replaced the 0 check and added tests to cover both the missing-profile case and a real failure HRESULT.

[velocitysystems]

Can we please ignore src-tauri/gen and remove this folder from source control? This is ignored in our other plugin repositories.

[gabref]

Updated the example app ignore rules to include src-tauri/gen, and removed that generated directory from source control so it won’t keep showing up in the repo.

[velocitysystems]

Can we please undo this unrelated change?

[gabref]

Yes, I’ll drop this from the PR. I changed it because the ${...:-...} expansion doesn’t work in PowerShell, but that’s separate from the scope here. I’ll keep the local workaround for now and we can handle a cross-shell commitlint fix in a follow-up PR.

[velocitysystems]

Interesting. We may need to revisit this elsewhere; Mac vs Windows I guess.

[velocitysystems]

Can we please roll this back to 0.1.41 to match our other plugins?

[gabref]

Rolled back to 0.1.41 to match the other plugins.

One note: our main app currently has tracing = "0.1.44", so that may be intentional there, but I’ve aligned this plugin with the plugin repos as requested.

[velocitysystems]

Nit: This pattern can be simplified using inspect_err:

let connection_cost = profile   
   .GetConnectionCost()                                                                                                                                                                              
   .inspect_err(|error| warn!(%error, "failed to query Windows connection cost"))?;

This could be applied also to the other properties too.

[gabref]

Good suggestion! Updated the straightforward error paths.