Add postgres-mcp Helm chart

Wraps FreePeak/db-mcp-server: multi-database Postgres MCP driven by a
single JSON connection list, so new databases don't need a new Helm
release. Includes per-connection read_only/max_rows/query_timeout/
masking_rules guardrails and a PVC-backed audit log.

postgres-mcp/Chart.yaml

@@ -0,0 +1,9 @@
+apiVersion: v2
+name: postgres-mcp
+description: Multi-database Postgres MCP server Helm chart (FreePeak/db-mcp-server)
+type: application
+version: 0.1.0
+appVersion: "1.9.0"
+annotations:
+  version-source: github-release:FreePeak/db-mcp-server
+  version-pattern: "s|^v||"