Add shared Kubernetes configuration files

- Add k8s/configmap.yaml with shared environment variables
- Add k8s/lpt-secrets.yaml template (secrets not committed)
- Add k8s/regcred-secret.yaml template (managed by workflow)
- Add k8s/README.md with deployment instructions
- Remove incorrect deployment/service files from root k8s/

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

k8s/lpt-secrets.yaml

@@ -0,0 +1,33 @@
+# LPT Application Secrets
+#
+# This file is a TEMPLATE - DO NOT commit real secrets to git!
+#
+# To create this secret:
+# kubectl create secret generic lpt-secrets \
+#   --from-literal=llm-api-key=<YOUR_LLM_API_KEY> \
+#   --from-literal=mysql-root-password=<YOUR_MYSQL_ROOT_PASSWORD> \
+#   --namespace=lpt-dev
+#
+# Or use kubectl apply with stringData:
+# kubectl apply -f - <<EOF
+# apiVersion: v1
+# kind: Secret
+# metadata:
+#   name: lpt-secrets
+#   namespace: lpt-dev
+# type: Opaque
+# stringData:
+#   llm-api-key: "your-actual-api-key"
+#   mysql-root-password: "your-actual-mysql-password"
+# EOF
+
+apiVersion: v1
+kind: Secret
+metadata:
+  name: lpt-secrets
+  namespace: lpt-dev
+type: Opaque
+data:
+  # Base64 encoded values - use stringData for plain text when applying
+  # llm-api-key: <base64-encoded-api-key>
+  # mysql-root-password: <base64-encoded-password>