fix(indexes): report unique violations from index creation as Unique

Postgres, MariaDB/MySQL and Mongo now map a unique violation raised by createIndex() to UniqueException directly instead of relying on processException() to parse the violated key. On Postgres a nested object path key is an expression, and on MariaDB/MySQL a localized message names no key, so both came back as a plain DuplicateException that Database::createIndex() tolerated as an existing index, keeping metadata for an index that was never built. "Index already exists" and document-level duplicates are unchanged.

Author: HarshMN2345

src/Database/Adapter/MariaDB.php

@@ -779,6 +779,12 @@ public function createIndex(string $collection, string $id, string $type, array
                 ->prepare($sql)
                 ->execute();
         } catch (PDOException $e) {
+            // Existing rows violate the new unique index. Classified here because
+            // processException() can't parse the key from a localized message.
+            if ($e->getCode() === '23000' && isset($e->errorInfo[1]) && $e->errorInfo[1] === 1062) {
+                throw new UniqueException('Unique index violation', $e->getCode(), $e);
+            }
+
             throw $this->processException($e);
         }
     }

src/Database/Adapter/Mongo.php

@@ -1146,6 +1146,11 @@ public function createIndex(string $collection, string $id, string $type, array
 
             return $result;
         } catch (\Exception $e) {
+            // Existing documents violate the new unique index, whatever index the message names
+            if ($e->getCode() === 11000 || $e->getCode() === 11001) {
+                throw new UniqueException('Unique index violation', $e->getCode(), $e);
+            }
+
             throw $this->processException($e);
         }
     }

src/Database/Adapter/Postgres.php

@@ -925,6 +925,12 @@ public function createIndex(string $collection, string $id, string $type, array
         try {
             return $this->getPDO()->prepare($sql)->execute();
         } catch (PDOException $e) {
+            // Existing rows violate the new unique index. Classified here because an
+            // expression key (nested object path) has no columns for processException() to parse.
+            if ($e->getCode() === '23505' && isset($e->errorInfo[1]) && $e->errorInfo[1] === 7) {
+                throw new UniqueException('Unique index violation', $e->getCode(), $e);
+            }
+
             throw $this->processException($e);
         }
     }