fix(users): an admin email edit must clear the stale verification

UpdateUser wrote a new address but kept email_verified, so patching a verified
account asserted a proof of an address nobody had proven — and the
pre-session login mails and resolves on exactly that flag, so a typo'd edit
could hand the account's sign-in codes to the wrong mailbox.

Changing the address now clears the flag in the same write; a no-op patch that
passes the same value keeps it. The fake mirrors the semantics, and the pgint
suite pins both halves (same value keeps proof, new value drops it).

internal/api/api_test.go

@@ -921,6 +921,12 @@ func (f *fakeRepo) UpdateUser(_ context.Context, userID string, patch UpdateUser
 			f.seededUsers[i].detail.Username = *patch.Username
 		}
 		if patch.Email != nil {
+			// Changing the address voids the proof of it, exactly like PGRepo:
+			// only VerifyEmailOTP may assert a verified address.
+			if *patch.Email != f.seededUsers[i].view.Email {
+				f.seededUsers[i].view.EmailVerified = false
+				f.seededUsers[i].detail.EmailVerified = false
+			}
 			f.seededUsers[i].view.Email = *patch.Email
 			f.seededUsers[i].detail.Email = *patch.Email
 		}