feat: full tenant cleanup on delete — Docker resources, PG schema, CH data (#55)

DockerTenantProvisioner.remove() now cleans up all tenant Docker resources:
containers (by cameleer.tenant label), env networks, tenant network, JAR volume.
TenantDataCleanupService drops the tenant's PostgreSQL schema and deletes all
ClickHouse data for GDPR compliance.

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

pom.xml

@@ -80,6 +80,14 @@
             <artifactId>spring-boot-starter-actuator</artifactId>
         </dependency>
 
+        <!-- ClickHouse JDBC (tenant data cleanup on delete) -->
+        <dependency>
+            <groupId>com.clickhouse</groupId>
+            <artifactId>clickhouse-jdbc</artifactId>
+            <version>0.9.7</version>
+            <classifier>all</classifier>
+        </dependency>
+
         <!-- Docker Java (tenant provisioning) -->
         <dependency>
             <groupId>com.github.docker-java</groupId>