[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/chart_values.tpl

@@ -0,0 +1,17 @@
+tls:
+  useSelfSigned: true
+credentials:
+  root:
+    password: ${root_password}
+    user: root
+serverInstances: 1
+podSpec:
+ containers:
+ - name: mysql
+   resources:
+     requests:
+       memory: "1024Mi"  # adapt to your needs
+       cpu: "1800m"      # adapt to your needs
+     limits:
+       memory: "2048Mi"  # adapt to your needs
+       cpu: "3600m"      # adapt to your needs