chore: update docs and config for PostgreSQL/OpenSearch storage layer

- Set failsafe reuseForks=true to reuse JVM across IT classes (faster test suite)
- Replace ClickHouse with PostgreSQL+OpenSearch in docker-compose.yml
- Remove redundant docker-compose.dev.yml
- Update CLAUDE.md and HOWTO.md to reflect new storage stack

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

HOWTO.md

@@ -21,20 +21,20 @@ mvn clean verify           # compile + run all tests (needs Docker for integrati
 
 ## Infrastructure Setup
 
-Start ClickHouse:
+Start PostgreSQL and OpenSearch:
 
 ```bash
 docker compose up -d
 ```
 
-This starts ClickHouse 25.3 and automatically runs the schema init scripts (`clickhouse/init/01-schema.sql`, `clickhouse/init/02-search-columns.sql`, `clickhouse/init/03-users.sql`).
+This starts TimescaleDB (PostgreSQL 16) and OpenSearch 2.19. The database schema is applied automatically via Flyway migrations on server startup.
 
-| Service    | Port | Purpose          |
-|------------|------|------------------|
-| ClickHouse | 8123 | HTTP API (JDBC)  |
-| ClickHouse | 9000 | Native protocol  |
+| Service    | Port | Purpose              |
+|------------|------|----------------------|
+| PostgreSQL | 5432 | JDBC (Spring JDBC)   |
+| OpenSearch | 9200 | REST API (full-text)  |
 
-ClickHouse credentials: `cameleer` / `cameleer_dev`, database `cameleer3`.
+PostgreSQL credentials: `cameleer` / `cameleer_dev`, database `cameleer3`.
 
 ## Run the Server
 
@@ -109,7 +109,7 @@ The env-var local user gets `ADMIN` role. Agents get `AGENT` role at registratio
 
 ### OIDC Login (Optional)
 
-OIDC configuration is stored in ClickHouse and managed via the admin API or UI. The SPA checks if OIDC is available:
+OIDC configuration is stored in PostgreSQL and managed via the admin API or UI. The SPA checks if OIDC is available:
 
 ```bash
 # 1. SPA checks if OIDC is available (returns 404 if not configured)
@@ -340,9 +340,8 @@ Key settings in `cameleer3-server-app/src/main/resources/application.yml`:
 |---------|---------|-------------|
 | `server.port` | 8081 | Server port |
 | `ingestion.buffer-capacity` | 50000 | Max items in write buffer |
-| `ingestion.batch-size` | 5000 | Items per ClickHouse batch insert |
+| `ingestion.batch-size` | 5000 | Items per batch insert |
 | `ingestion.flush-interval-ms` | 1000 | Buffer flush interval (ms) |
-| `ingestion.data-ttl-days` | 30 | ClickHouse TTL for auto-deletion |
 | `agent-registry.heartbeat-interval-seconds` | 30 | Expected heartbeat interval |
 | `agent-registry.stale-threshold-seconds` | 90 | Time before agent marked STALE |
 | `agent-registry.dead-threshold-seconds` | 300 | Time after STALE before DEAD |
@@ -386,7 +385,7 @@ npm run generate-api   # Requires backend running on :8081
 
 ## Running Tests
 
-Integration tests use Testcontainers (starts ClickHouse automatically — requires Docker):
+Integration tests use Testcontainers (starts PostgreSQL and OpenSearch automatically — requires Docker):
 
 ```bash
 # All tests
@@ -399,14 +398,13 @@ mvn test -pl cameleer3-server-core
 mvn test -pl cameleer3-server-app -Dtest=ExecutionControllerIT
 ```
 
-## Verify ClickHouse Data
+## Verify Database Data
 
 After posting data and waiting for the flush interval (1s default):
 
 ```bash
-docker exec -it cameleer3-server-clickhouse-1 clickhouse-client \
-  --user cameleer --password cameleer_dev -d cameleer3 \
-  -q "SELECT count() FROM route_executions"
+docker exec -it cameleer3-server-postgres-1 psql -U cameleer -d cameleer3 \
+  -c "SELECT count(*) FROM route_executions"
 ```
 
 ## Kubernetes Deployment
@@ -417,7 +415,8 @@ The full stack is deployed to k3s via CI/CD on push to `main`. K8s manifests are
 
 ```
 cameleer namespace:
-  ClickHouse (StatefulSet, 2Gi PVC)        ← clickhouse:8123 (ClusterIP)
+  PostgreSQL (StatefulSet, 10Gi PVC)       ← postgres:5432 (ClusterIP)
+  OpenSearch (StatefulSet, 10Gi PVC)       ← opensearch:9200 (ClusterIP)
   cameleer3-server (Deployment)            ← NodePort 30081
   cameleer3-ui (Deployment, Nginx)         ← NodePort 30090
   Authentik Server (Deployment)            ← NodePort 30950
@@ -439,7 +438,7 @@ cameleer namespace:
 
 Push to `main` triggers: **build** (UI npm + Maven, unit tests) → **docker** (buildx amd64 for server + UI, push to Gitea registry) → **deploy** (kubectl apply + rolling update).
 
-Required Gitea org secrets: `REGISTRY_TOKEN`, `KUBECONFIG_BASE64`, `CAMELEER_AUTH_TOKEN`, `CAMELEER_JWT_SECRET`, `CLICKHOUSE_USER`, `CLICKHOUSE_PASSWORD`, `CAMELEER_UI_USER` (optional), `CAMELEER_UI_PASSWORD` (optional), `AUTHENTIK_PG_PASSWORD`, `AUTHENTIK_SECRET_KEY`, `CAMELEER_OIDC_ENABLED`, `CAMELEER_OIDC_ISSUER`, `CAMELEER_OIDC_CLIENT_ID`, `CAMELEER_OIDC_CLIENT_SECRET`.
+Required Gitea org secrets: `REGISTRY_TOKEN`, `KUBECONFIG_BASE64`, `CAMELEER_AUTH_TOKEN`, `CAMELEER_JWT_SECRET`, `POSTGRES_USER`, `POSTGRES_PASSWORD`, `POSTGRES_DB`, `OPENSEARCH_USER`, `OPENSEARCH_PASSWORD`, `CAMELEER_UI_USER` (optional), `CAMELEER_UI_PASSWORD` (optional), `AUTHENTIK_PG_USER`, `AUTHENTIK_PG_PASSWORD`, `AUTHENTIK_SECRET_KEY`, `CAMELEER_OIDC_ENABLED`, `CAMELEER_OIDC_ISSUER`, `CAMELEER_OIDC_CLIENT_ID`, `CAMELEER_OIDC_CLIENT_SECRET`.
 
 ### Manual K8s Commands
 
@@ -450,8 +449,11 @@ kubectl -n cameleer get pods
 # View server logs
 kubectl -n cameleer logs -f deploy/cameleer3-server
 
-# View ClickHouse logs
-kubectl -n cameleer logs -f statefulset/clickhouse
+# View PostgreSQL logs
+kubectl -n cameleer logs -f statefulset/postgres
+
+# View OpenSearch logs
+kubectl -n cameleer logs -f statefulset/opensearch
 
 # Restart server
 kubectl -n cameleer rollout restart deployment/cameleer3-server