fix: derive PG schema from tenant ID instead of defaulting to public

Schema now defaults to tenant_${cameleer.tenant.id} (e.g. tenant_default,
tenant_acme) instead of public. Flyway create-schemas: true ensures the
schema is auto-created on first startup. CAMELEER_DB_SCHEMA env var still
available as override for feature branch isolation. Removed hardcoded
public schema from K8s base and main overlay.

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

cameleer3-server-app/src/main/resources/application.yml

@@ -3,18 +3,19 @@ server:
 
 spring:
   datasource:
-    url: jdbc:postgresql://localhost:5432/cameleer3?currentSchema=${CAMELEER_DB_SCHEMA:public}
+    url: jdbc:postgresql://localhost:5432/cameleer3?currentSchema=${CAMELEER_DB_SCHEMA:tenant_${cameleer.tenant.id}}
     username: cameleer
     password: ${CAMELEER_DB_PASSWORD:cameleer_dev}
     driver-class-name: org.postgresql.Driver
   flyway:
     enabled: true
     locations: classpath:db/migration
-    url: jdbc:postgresql://localhost:5432/cameleer3?currentSchema=${CAMELEER_DB_SCHEMA:public},public
+    url: jdbc:postgresql://localhost:5432/cameleer3?currentSchema=${CAMELEER_DB_SCHEMA:tenant_${cameleer.tenant.id}},public
     user: ${spring.datasource.username}
     password: ${spring.datasource.password}
-    schemas: ${CAMELEER_DB_SCHEMA:public}
-    default-schema: ${CAMELEER_DB_SCHEMA:public}
+    schemas: ${CAMELEER_DB_SCHEMA:tenant_${cameleer.tenant.id}}
+    default-schema: ${CAMELEER_DB_SCHEMA:tenant_${cameleer.tenant.id}}
+    create-schemas: true
   mvc:
     async:
       request-timeout: -1