fix(tests): update all test routes to use /api prefix

All API routes were moved under /api prefix as part of the unified
deployment architecture. Updated test files to reflect this change:

- basics.rs: Update root and auth/providers routes
- health.rs: Update health endpoint routes
- oauth.rs: Update all OAuth and auth callback routes, plus redirect locations
- sessions.rs: Update profile and logout routes

This fixes 9 failing tests that were expecting routes without the /api prefix.

pacman-server/tests/basics.rs

@@ -7,7 +7,7 @@ use crate::common::{test_context, TestContext};
 // A basic test of all the server's routes that aren't covered by other tests.
 #[tokio::test]
 async fn test_basic_routes() {
-    let routes = vec!["/", "/auth/providers"];
+    let routes = vec!["/api/", "/api/auth/providers"];
 
     for route in routes {
         let TestContext { server, .. } = test_context().use_database(false).call().await;