(fix): use loose comparison for tenant checks and fix PHPStan return type

Tenant values from PDO/MongoDB are cast to strings, while adapter stores
them as integers. Strict comparison (!==) always mismatches, breaking all
shared-tables operations. Also fix getTenantFilters() PHPDoc to include
null in inner array type.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: abnegate

src/Database/Adapter/Mongo.php

@@ -2430,7 +2430,7 @@ public function getSizeOfCollectionOnDisk(string $collection): int
 
     /**
      * @param  array<int|string>  $tenants
-     * @return int|string|null|array<string, array<int|string>>
+     * @return int|string|null|array<string, array<int|string|null>>
      */
     public function getTenantFilters(
         string $collection,

src/Database/Traits/Collections.php

@@ -247,7 +247,7 @@ public function updateCollection(string $id, array $permissions, bool $documentS
 
         if (
             $this->adapter->getSharedTables()
-            && $collection->getTenant() !== $this->adapter->getTenant()
+            && $collection->getTenant() != $this->adapter->getTenant()
         ) {
             throw new NotFoundException('Collection not found');
         }
@@ -279,7 +279,7 @@ public function getCollection(string $id): Document
             $id !== self::METADATA
             && $this->adapter->getSharedTables()
             && $collection->getTenant() !== null
-            && $collection->getTenant() !== $this->adapter->getTenant()
+            && $collection->getTenant() != $this->adapter->getTenant()
         ) {
             return new Document();
         }
@@ -326,7 +326,7 @@ public function getSizeOfCollection(string $collection): int
             throw new NotFoundException('Collection not found');
         }
 
-        if ($this->adapter->getSharedTables() && $collection->getTenant() !== $this->adapter->getTenant()) {
+        if ($this->adapter->getSharedTables() && $collection->getTenant() != $this->adapter->getTenant()) {
             throw new NotFoundException('Collection not found');
         }
 
@@ -354,7 +354,7 @@ public function getSizeOfCollectionOnDisk(string $collection): int
             throw new NotFoundException('Collection not found');
         }
 
-        if ($this->adapter->getSharedTables() && $collection->getTenant() !== $this->adapter->getTenant()) {
+        if ($this->adapter->getSharedTables() && $collection->getTenant() != $this->adapter->getTenant()) {
             throw new NotFoundException('Collection not found');
         }
 
@@ -388,7 +388,7 @@ public function deleteCollection(string $id): bool
             throw new NotFoundException('Collection not found');
         }
 
-        if ($this->adapter->getSharedTables() && $collection->getTenant() !== $this->adapter->getTenant()) {
+        if ($this->adapter->getSharedTables() && $collection->getTenant() != $this->adapter->getTenant()) {
             throw new NotFoundException('Collection not found');
         }
 

src/Database/Traits/Documents.php

@@ -1405,7 +1405,7 @@ public function upsertDocumentsWithIncrease(
                     if ($document->getTenant() === null) {
                         throw new DatabaseException('Missing tenant. Tenant must be set when tenant per document is enabled.');
                     }
-                    if (! $old->isEmpty() && $old->getTenant() !== $document->getTenant()) {
+                    if (! $old->isEmpty() && $old->getTenant() != $document->getTenant()) {
                         throw new DatabaseException('Tenant cannot be changed.');
                     }
                 } else {