add audit archiver environment variables

Author: maxmalkin

.env.example

@@ -138,6 +138,32 @@ REGISTRY_URL=http://localhost:8080
 # Port for the approval UI server (default 3000; use 3001 to avoid Grafana conflict)
 PORT=3001
 
+# =============================================================================
+# Audit Archiver
+# =============================================================================
+
+# Database connection (uses primary — archiver runs DDL)
+ARCHIVER__DATABASE__URL=postgres://agentauth:agentauth_dev@localhost:5434/agentauth
+ARCHIVER__DATABASE__MAX_CONNECTIONS=4
+ARCHIVER__DATABASE__CONNECT_TIMEOUT_SECS=5
+
+# Cold storage backend: "s3" or "local_fs"
+ARCHIVER__STORAGE__BACKEND=s3
+ARCHIVER__STORAGE__S3_BUCKET=agentauth-audit-archive
+ARCHIVER__STORAGE__S3_PREFIX=audit-archive/
+# Override endpoint for MinIO in local dev
+ARCHIVER__STORAGE__S3_ENDPOINT_URL=http://localhost:9000
+ARCHIVER__STORAGE__S3_REGION=us-east-1
+# Local filesystem path (when backend=local_fs)
+# ARCHIVER__STORAGE__LOCAL_PATH=./tmp/audit-archive
+
+# Retention policy
+ARCHIVER__RETENTION__HOT_RETENTION_DAYS=90
+ARCHIVER__RETENTION__ADVANCE_PARTITION_DAYS=7
+
+# Observability
+ARCHIVER__OBSERVABILITY__LOG_LEVEL=info
+
 # =============================================================================
 # Development Only
 # =============================================================================