E2E Test for Email Signup/Login Flow

**Goal**
We want to be able to automatically test the authentication flow to build confidence in the basic functioning of the site after deploys.

**Success Criteria:**
- Add a Playwright Test that confirms we can successfully create and log in to individual user accounts
- Flow should be:
- Create new account with email / password
- Sign out
- Sign back in (to confirm login works)
- Delete account (to clean up after tests)

**Exclusions:**

There are currently three signup flows on the site:
- Individual User signing up with Email / Password
- Individual User signing up with Google Auth
- Organization signing up with Email / Password

This card only covers the first flow (Individual users signing up with Email / Password).