fix: tenant as string, rewrite tests for new API, audit fixes

- Change tenant type from ?int to ?string everywhere (Adapter, Usage,
  ClickHouse, Database, Metric)
- ClickHouse tenant column: Nullable(String) instead of Nullable(UInt64)
- Fix tenant key mismatch: validateMetricsBatch now checks '$tenant'
  matching resolveTenantFromMetric
- Fix MV GROUP BY: conditional on sharedTables (no tenant column when
  sharedTables=false)
- Fix billing/daily target tables: conditional tenant column and ORDER BY
- Add collect() validation: empty metric name and negative value checks
- Fix ltrim() misuse in buildWhereClause: getTenantFilter now returns
  bare condition without ' AND ' prefix
- Fix SQL.php: replace 'Audit' references with 'Usage', remove unused
  Database import
- Fix parseQueries: use Int64 param type for value attribute instead of
  String
- Rewrite all tests (UsageBase, ClickHouseTest, MetricTest) for new API:
  replace increment/set/period-based methods with addBatch/collect/
  getTotal/getTotalBatch/getTimeSeries

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

Author: lohanidamodar

src/Usage/Adapter.php

@@ -115,10 +115,10 @@ abstract public function setNamespace(string $namespace): self;
     /**
      * Set the tenant ID for multi-tenant support.
      *
-     * @param int|null $tenant
+     * @param string|null $tenant
      * @return self
      */
-    abstract public function setTenant(?int $tenant): self;
+    abstract public function setTenant(?string $tenant): self;
 
     /**
      * Enable or disable shared tables mode (multi-tenant with tenant column).

src/Usage/Adapter/ClickHouse.php

@@ -372,10 +372,10 @@ public function setNamespace(string $namespace): self
     /**
      * Set the tenant ID for multi-tenant support.
      *
-     * @param int|null $tenant
+     * @param string|null $tenant
      * @return self
      */
-    public function setTenant(?int $tenant): self
+    public function setTenant(?string $tenant): self
     {
         $this->db->setTenant($tenant);
         return $this;

src/Usage/Adapter/Database.php

@@ -4,11 +4,10 @@
 
 use Utopia\Usage\Adapter;
 use Utopia\Usage\Metric;
-use Utopia\Database\Database;
 use Utopia\Database\Document;
 
 /**
- * Base SQL Adapter for Audit
+ * Base SQL Adapter for Usage
  *
  * This is an abstract base class for SQL-based adapters (Database, ClickHouse, etc.)
  * It provides common functionality and references schema definitions from the Metric class.
@@ -18,7 +17,7 @@ abstract class SQL extends Adapter
     public const COLLECTION = 'usage';
 
     /**
-     * Get the collection/table name for audit logs.
+     * Get the collection/table name for usage metrics.
      *
      * @return string
      */
@@ -28,7 +27,7 @@ public function getCollectionName(): string
     }
 
     /**
-     * Get attribute definitions for audit logs.
+     * Get attribute definitions for usage metrics.
      *
      * Delegates to Metric class which defines the metric schema.
      *
@@ -40,7 +39,7 @@ public function getAttributes(): array
     }
 
     /**
-     * Get attribute documents for audit logs.
+     * Get attribute documents for usage metrics.
      *
      * @return array<Document>
      */
@@ -50,7 +49,7 @@ public function getAttributeDocuments(): array
     }
 
     /**
-     * Get index definitions for audit logs.
+     * Get index definitions for usage metrics.
      *
      * Delegates to Metric class which defines the metric indexes.
      *
@@ -62,7 +61,7 @@ public function getIndexes(): array
     }
 
     /**
-     * Get index documents for audit logs.
+     * Get index documents for usage metrics.
      *
      * @return array<Document>
      */

src/Usage/Adapter/SQL.php

@@ -153,25 +153,17 @@ public function getTags(): array
      * architectures. This allows data isolation at the application level while
      * sharing the same database tables.
      *
-     * @return int|null The tenant ID, or null if not set or not using multi-tenancy
+     * @return string|null The tenant ID, or null if not set or not using multi-tenancy
      */
-    public function getTenant(): ?int
+    public function getTenant(): ?string
     {
         $tenant = $this->getAttribute('tenant');
 
         if ($tenant === null) {
             return null;
         }
 
-        if (is_int($tenant)) {
-            return $tenant;
-        }
-
-        if (is_numeric($tenant)) {
-            return (int) $tenant;
-        }
-
-        return null;
+        return (string) $tenant;
     }
 
     /**

src/Usage/Metric.php

@@ -201,10 +201,10 @@ public function setNamespace(string $namespace): self
     /**
      * Set the tenant ID for multi-tenant support.
      *
-     * @param int|null $tenant
+     * @param string|null $tenant
      * @return $this
      */
-    public function setTenant(?int $tenant): self
+    public function setTenant(?string $tenant): self
     {
         $this->adapter->setTenant($tenant);
         return $this;
@@ -237,6 +237,12 @@ public function setSharedTables(bool $sharedTables): self
      */
     public function collect(string $metric, int $value, string $type, array $tags = []): self
     {
+        if (empty($metric)) {
+            throw new \InvalidArgumentException('Metric name cannot be empty');
+        }
+        if ($value < 0) {
+            throw new \InvalidArgumentException('Value cannot be negative');
+        }
         if ($type !== self::TYPE_EVENT && $type !== self::TYPE_GAUGE) {
             throw new \InvalidArgumentException("Invalid metric type '{$type}'. Allowed: " . self::TYPE_EVENT . ', ' . self::TYPE_GAUGE);
         }