Prepare local dev for tenant DB switching

- Add .env.local to .gitignore (gitignored local overrides for DB_HOST/DB_PORT)
- Load .env.local with override in node tests — create this file to point at
  local MariaDB (DB_HOST=localhost DB_PORT=30310) instead of VPS via WireGuard
- MariaDB NodePorts added to K8s manifests (infra/k8s/local/):
  mariadb dev: 30310, mariadb-test: 30311

Workflow: dump tenant DB → load into local mariadb pod → set .env.local → run node tests locally

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

.gitignore

@@ -2,4 +2,7 @@
 __pycache__/
 *.pyc
 .env
+.env.local
 trace.jsonl
+docker/mariadb/*.sql.gz
+docker/mariadb/dump_*.sql

tests/test_node_eras.py

@@ -16,9 +16,15 @@ import os
 import sys
 from pathlib import Path
 
-# Load .env so DB_HOST, OPENROUTER_API_KEY etc. are set
+# Load .env then .env.local (override) so DB_HOST, OPENROUTER_API_KEY etc. are set.
+# .env.local is gitignored — use it to point at a local tenant DB:
+#   DB_HOST=localhost
+#   DB_PORT=30310   (mariadb NodePort, dev namespace)
+#   DB_PORT=30311   (mariadb-test NodePort, test namespace)
 from dotenv import load_dotenv
-load_dotenv(Path(__file__).parent.parent / ".env")
+_root = Path(__file__).parent.parent
+load_dotenv(_root / ".env")
+load_dotenv(_root / ".env.local", override=True)
 
 sys.path.insert(0, str(Path(__file__).parent.parent))