Repair verification joins broken by the OTP key change; extend backfill

Storing the verification phone as a keyed HMAC fixed OTP lookups but broke
every query that joined those tables back to the account, because
phone_verification*.phone_number no longer holds the same value as
driver.phone / passengers.phone. Six joins were affected, and four of them
feed the `verified` flag that the rider and driver apps check at sign-in — so
this was already failing under the current CBC mode, not only after a switch
to GCM.

Accounts now carry phone_key, computed exactly as otpPhoneKey() does, and the
joins match on it. It is written at registration for both apps and populated
for existing rows by the backfill.

The backfill also covers the columns added for the remaining lookups:
users.email_bidx/phone_bidx and driver.national_bidx, which were migrated but
never populated, and honours a per-field prefix so phone_key reproduces
otpPhoneKey's exact output.

Insert column/value counts verified with a paren-aware parser after editing.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

backend/auth/driver/loginUsingCredentialsWithoutGoogle.php

@@ -52,7 +52,7 @@ try {
         CarRegistration.model,
         CarRegistration.year
     FROM driver
-    LEFT JOIN phone_verification ON phone_verification.phone_number = driver.phone
+    LEFT JOIN phone_verification ON phone_verification.phone_number = driver.phone_key
     LEFT JOIN CarRegistration ON CarRegistration.driverID = driver.id
     WHERE
         driver.email = :email