[6.x] Front-end login route

[brianjhanson]

Exposes a POST to your loginPath setting when front-end registration is enabled. Front-end login forms should post to that path to attempt a log in.

This also fixed some odd behavior I saw when logging out where I was getting redirected back to the previous page instead of dumped on the homepage (as was the case in Craft 5).

Fixes a lil' bug with deleting the home route from the UI that I noticed along the way

[Copilot]

Pull request overview

This PR exposes a front-end POST route at the configured loginPath (when front-end user routes are enabled), adjusts logout redirect behavior to consistently honor postLogoutRedirect (defaulting to the site root), and hardens route deletion event payloads when a route is missing uriParts.

Changes:

• Add POST routing for front-end logins at loginPath.
• Fix logout redirects to use postLogoutRedirect (or site root) rather than falling back to back().
• Prevent errors when deleting routes that don’t have uriParts set, and add feature tests for logout redirect behavior.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 1 comment.

File	Description
routes/web.php	Registers a new POST route for loginPath to support front-end login form submissions.
src/Http/Controllers/Auth/LoginController.php	Updates non-JSON logout responses to redirect to the site URL for postLogoutRedirect.
tests/Feature/Http/Controllers/Auth/LoginControllerTest.php	Adds tests ensuring logout redirects don’t fall back to the referrer and honor configured redirects.
src/Route/Routes.php	Makes route deletion events resilient when uriParts is missing in project config data.

[linear-code]

CMS-2264