Signing for Mac & PR builds

[SeanKilleen]

Resolves #50 (I think/hope)

Per https://tauri.studio/docs/distribution/sign-macos.

On My Local (Windows)

• Created cert on apple dev portal
• Created app specific password for my account for signing
• Downloaded the certificate
• Exported a PFX file on windows (and renamed to p12; apparently they're the same format. We'll see.)
• Encoded a text file of the cert
• Added the signing identity (full name on the cert entry), my apple id, the app password for the account, the text of the cert, and the cert password, etc. to secrets for GitHub actions.

In this PR

• Added the env variables to the build process

ℹ️ Note that in the Tauri docs example here, it assumes only a macos build. It's possible that adding these variables in all matrixed builds may screw things up at first and we may need to find a way to wrap them in an if statement or two separate build steps based on matrix (or Tauri may be smart enough to pick that up.)

[SeanKilleen]

@RyKilleen do you want me to also set up PR builds as part of this? I'd hate to merge it and find out it screws things up.

https://github.com/tauri-apps/tauri-action#testing-the-build

[RyKilleen]

Always a great practice, thanks for setting that up!

[RyKilleen]

Regarding your comment around if statements, the matrix.platform should give us whatever we need to sign on Mac only the way we do for Windows

[SeanKilleen]

Figured out an issue. Tauri doesn't have its env variable aligned with its secret name in one case. I'll PR their docs again after I verify the fix.

[SeanKilleen]

OK I can't spend more time on this at the moment but I think the issue is that I created a Distribution certificate rather than a developer ID certificate. I should be able to remedy that when I free up and then I think this process should work.

[SeanKilleen]

Looks like we're good to go now! @RyKilleen, merge when ready.

[RyKilleen]

I'll bump versions and rebase the branch if you're alright with that

[SeanKilleen]

@RyKilleen do it! 👍