[ci skip] Move Terraform modules into stack directories

Move all 88 service modules (66 individual + 22 platform) from
modules/kubernetes/<service>/ into their corresponding stack directories:

- Service stacks: stacks/<service>/module/
- Platform stack: stacks/platform/modules/<service>/

This collocates module source code with its Terragrunt definition.
Only shared utility modules remain in modules/kubernetes/:
ingress_factory, setup_tls_secret, dockerhub_secret, oauth-proxy.

All cross-references to shared modules updated to use correct
relative paths. Verified with terragrunt run --all -- plan:
0 adds, 0 destroys across all 68 stacks.

stacks/platform/modules/dbaas/mysql_chart_values.yaml

@@ -0,0 +1,14 @@
+---
+orchestrator:
+  # persistence:
+    # enabled: false
+  ingress:
+    enable: false
+    hosts:
+    - host: db.viktorbarzin.me
+      paths:
+      - path: /
+    tls:
+    - secretName: ${secretName}
+      hosts:
+        - db.viktorbarzin.me