feat: remove TimescaleDB, dead PG stores, and storage feature flags

Complete the ClickHouse migration by removing all PostgreSQL analytics
code. PostgreSQL now serves only RBAC, config, and audit — all
observability data is exclusively in ClickHouse.

- Delete 6 dead PostgreSQL store classes (executions, stats, diagrams,
  events, metrics, metrics-query) and 2 integration tests
- Delete RetentionScheduler (ClickHouse TTL handles retention)
- Remove all 7 cameleer.storage.* feature flags from application.yml
- Remove all @ConditionalOnProperty from ClickHouse beans in StorageBeanConfig
- Consolidate 14 Flyway migrations (V1-V14) into single clean V1 with
  only RBAC/config/audit tables (no TimescaleDB, no analytics tables)
- Switch from timescale/timescaledb-ha:pg16 to postgres:16 everywhere
  (docker-compose, deploy/postgres.yaml, test containers)
- Remove TimescaleDB check and /metrics-pipeline from DatabaseAdminController
- Set clickhouse.enabled default to true

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

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

@@ -42,15 +42,6 @@ cameleer:
   indexer:
     debounce-ms: ${CAMELEER_INDEXER_DEBOUNCE_MS:2000}
     queue-size: ${CAMELEER_INDEXER_QUEUE_SIZE:10000}
-  retention-days: ${CAMELEER_RETENTION_DAYS:30}
-  storage:
-    metrics: ${CAMELEER_STORAGE_METRICS:postgres}
-    search: ${CAMELEER_STORAGE_SEARCH:clickhouse}
-    stats: ${CAMELEER_STORAGE_STATS:clickhouse}
-    diagrams: ${CAMELEER_STORAGE_DIAGRAMS:clickhouse}
-    events: ${CAMELEER_STORAGE_EVENTS:clickhouse}
-    logs: ${CAMELEER_STORAGE_LOGS:clickhouse}
-    executions: ${CAMELEER_STORAGE_EXECUTIONS:clickhouse}
 
 security:
   access-token-expiry-ms: 3600000
@@ -70,7 +61,7 @@ springdoc:
     path: /api/v1/swagger-ui
 
 clickhouse:
-  enabled: ${CLICKHOUSE_ENABLED:false}
+  enabled: ${CLICKHOUSE_ENABLED:true}
   url: ${CLICKHOUSE_URL:jdbc:clickhouse://localhost:8123/cameleer}
   username: ${CLICKHOUSE_USERNAME:default}
   password: ${CLICKHOUSE_PASSWORD:}