Migrate remaining encrypted-column lookups to the blind index

Completes the set of queries that matched a freshly encrypted value against a
stored one, which only works while encryption is deterministic. Each keeps its
original comparison and adds an index comparison in the same WHERE, so nothing
changes today.

- passenger sign-in by email, service-staff sign-in, Firebase token lookup
- driver lookup by phone and by national number
- admin ride lookup and ride monitor (both tables)
- nabeh: driver status, user resolution, ride history, complaint submission

transit_org_admins lives in the transit database and has no index column, so
login there falls back to decrypting the small set of active admins and
comparing normalised numbers.

Schema: adds users.email_bidx/phone_bidx and driver.national_bidx with their
indexes.

Verified that every :*_bidx placeholder introduced is actually bound — an
unbound one is a fatal error at request time, not a silent miss.

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

backend/transit/admin/login_request.php

@@ -22,6 +22,9 @@ if (transitIsOtpLocked($phone)) {
 }
 
 $phoneEnc = $encryptionHelper->encryptData($phone);
+// transit_org_admins يعيش في قاعدة المواصلات ولا يملك عمود فهرس بعد،
+// فتتم المطابقة على الرقم الأصلي بعد فك التشفير عند فشل المقارنة المباشرة.
+$phoneNorm = normalizePhone($phone);
 $st = $transit_con->prepare(
     "SELECT a.id, o.contract_status
      FROM transit_org_admins a
@@ -31,6 +34,24 @@ $st = $transit_con->prepare(
 $st->execute([$phoneEnc]);
 $admin = $st->fetch();
 
+if (!$admin) {
+    // تحت التشفير العشوائي لا تتطابق النصوص المشفّرة، فنقارن الأرقام الأصلية.
+    $all = $transit_con->query(
+        "SELECT a.id, a.phone, o.contract_status
+         FROM transit_org_admins a
+         JOIN transit_orgs o ON o.id = a.org_id
+         WHERE a.is_active = 1"
+    )->fetchAll(PDO::FETCH_ASSOC);
+
+    foreach ($all as $row) {
+        $plain = $encryptionHelper->decryptData($row['phone'] ?? null);
+        if ($plain && normalizePhone($plain) === $phoneNorm) {
+            $admin = $row;
+            break;
+        }
+    }
+}
+
 // لا نكشف إن كان الهاتف موجوداً أم لا — نفس الرد دائماً
 if (!$admin || $admin['contract_status'] === 'terminated') {
     jsonSuccess(null, 'OTP sent successfully');