fix: scope pg_stat_activity queries by ApplicationName for tenant isolation

DatabaseAdminController's active-queries and kill-query endpoints could
expose SQL text from other tenants sharing the same PostgreSQL instance.
Added ApplicationName=tenant_{id} to the JDBC URL and filter
pg_stat_activity by application_name so each tenant only sees its own
connections.

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

deploy/overlays/feature/kustomization.yaml

@@ -24,7 +24,7 @@ patches:
               - name: server
                 env:
                   - name: SPRING_DATASOURCE_URL
-                    value: "jdbc:postgresql://cameleer-postgres.cameleer.svc.cluster.local:5432/cameleer3?currentSchema=BRANCH_SCHEMA"
+                    value: "jdbc:postgresql://cameleer-postgres.cameleer.svc.cluster.local:5432/cameleer3?currentSchema=BRANCH_SCHEMA&ApplicationName=BRANCH_SCHEMA"
                   - name: CAMELEER_SERVER_SECURITY_UIORIGIN
                     value: "http://BRANCH_SLUG.cameleer.siegeln.net"
   # UI ConfigMap: branch-specific API URL

deploy/overlays/main/kustomization.yaml

@@ -41,7 +41,7 @@ patches:
                   - name: CAMELEER_SERVER_SECURITY_UIORIGIN
                     value: "http://192.168.50.86:30090"
                   - name: SPRING_DATASOURCE_URL
-                    value: "jdbc:postgresql://cameleer-postgres:5432/cameleer3?currentSchema=public"
+                    value: "jdbc:postgresql://cameleer-postgres:5432/cameleer3?currentSchema=public&ApplicationName=tenant_default"
   # UI ConfigMap: production API URL
   - target:
       kind: ConfigMap