[ci skip] Phase 1: PostgreSQL migrated to CNPG on local disk

Major milestone - shared PostgreSQL moved from NFS to CloudNativePG:
- CNPG cluster (pg-cluster) running in dbaas namespace on local-path storage
- PostGIS image (ghcr.io/cloudnative-pg/postgis:16) for dawarich compatibility
- All 20 databases and 19 roles restored from pg_dumpall backup
- postgresql.dbaas Service patched to point at CNPG primary
- Old PG deployment scaled to 0 (NFS data intact for rollback)
- All 12+ dependent services verified running:
  authentik, n8n, dawarich, tandoor, linkwarden, netbox, woodpecker,
  rybbit, affine, health, resume, trading-bot, atuin
- Authentik PgBouncer working through the switched endpoint

TODO: codify CNPG cluster in Terraform, add 2nd replica, update backup CronJob

stacks/trading-bot/tiers.tf

@@ -0,0 +1,10 @@
+# Generated by Terragrunt. Sig: nIlQXj57tbuaRZEa
+locals {
+  tiers = {
+    core    = "0-core"
+    cluster = "1-cluster"
+    gpu     = "2-gpu"
+    edge    = "3-edge"
+    aux     = "4-aux"
+  }
+}