Chore: address `@todo` in `do-auth` actions

[babblebey]

Leaving this here as reference for @todo

1. make the parsedState data more predictable (order by path, redirect)

   The intention of this is to avoid unpredictability in the value of the parsedState computed from...

   const parsedState = String(Object.keys(state).map(key => key + ":" + state[key]).join("|"));

   ... the value is expected to look like path:[value]|redirect:[value], and be ordered by path first, the redirect next (in cases where redirect is present in state) in order to allow correct consumption in the github oauth callback handler

   // src/pages/api/github/oauth/callback.js
   
   const path = state.includes("path") && state.split("|")[0].split(":")[1];
   const isRedirect = state.includes("redirect") ? state.split("|")[1].split(":")[1] : false;

   ...failure to adhere to this order will cause failure; the point of initialization where this order can be inputted in the wrong order is in the login page

   // src/pages/login.astro
   
   const authUrl = getAuthUrl({
     path: searchParams.get("redirect"),
     redirect: true
   });

   ... in cases where the path isn't stated as first value on the getAuthUrl argument object before the redirect; this will cause the error.

Originally posted by @babblebey in https://github.com/babblebey/jargons.dev/pull/8#discussion_r1545383948

[babblebey]

I will also consider doing the following:

• change the redirect property in the state object to return_to for readbility and seperation from the redirect function naming
• encode the pathname with the encodeURIComponent to remove the sense of the / in pathname parts of the url params