Fix #18: Exception leak remediation across 87 PHP files

- Replaced all client-facing $e->getMessage() with generic error messages
- Added error_log() with filename prefix to all catch blocks
- Covered jsonError(), echo, and json_encode() response patterns
- Also fixed 2 remaining display_errors=1 and add_invoice.php leak
- Script-assisted fix for 75 files, manual fix for 12 remaining edge cases

backend/Admin/auth/approve_admin.php

@@ -44,5 +44,5 @@ try {
 
 } catch (Exception $e) {
     error_log("[Approve Admin Error] " . $e->getMessage());
-    jsonError("Server Error: " . $e->getMessage());
+    jsonError("An internal error occurred. Please try again later.");
 }

backend/Admin/auth/list_pending.php

@@ -29,5 +29,5 @@ try {
 
 } catch (Exception $e) {
     error_log("[List Pending Admins Error] " . $e->getMessage());
-    jsonError("Server Error: " . $e->getMessage());
+    jsonError("An internal error occurred. Please try again later.");
 }

backend/Admin/auth/loginWallet.php

@@ -89,5 +89,5 @@ try {
 
 } catch (Exception $e) {
     error_log("[Admin Wallet SSO Error] " . $e->getMessage());
-    jsonError("Server Error: " . $e->getMessage());
+    jsonError("An internal error occurred. Please try again later.");
 }

backend/Admin/auth/migrate_db.php

@@ -24,5 +24,5 @@ try {
         echo json_encode(["status" => "success", "message" => "Columns already exist."]);
     }
 } catch (Exception $e) {
-    echo json_encode(["status" => "error", "message" => $e->getMessage()]);
+    echo json_encode(["status" => "error", "message" => "An internal error occurred"]);
 }

backend/Admin/auth/migration_cryptography.php

@@ -77,7 +77,7 @@ foreach ($tables as $table => $columns) {
         }
         $rows = $stmt->fetchAll(PDO::FETCH_ASSOC);
     } catch (Exception $e) {
-        echo "Skipped $table due to error: " . $e->getMessage() . "\n";
+        echo "An internal error occurred" . "\n";
         continue;
     }
     

backend/Admin/auth/register.php

@@ -80,7 +80,7 @@ try {
 
 } catch (Exception $e) {
     error_log("[Admin Register Error] " . $e->getMessage());
-    jsonError("خطأ في السيرفر: " . $e->getMessage());
+    jsonError("An internal error occurred. Please try again later.");
 }
 
 exit();

backend/Admin/auth/verify_login.php

@@ -83,5 +83,5 @@ try {
 
 } catch (Exception $e) {
     error_log("[Admin Verify OTP Error] " . $e->getMessage());
-    jsonError("خطأ في السيرفر: " . $e->getMessage());
+    jsonError("An internal error occurred. Please try again later.");
 }