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/configmap.yaml

@@ -0,0 +1,15 @@
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: lpt-config
+  namespace: lpt-dev
+data:
+  # LPT AI Service
+  LLM_API_URL: https://api.siliconflow.cn/v1/chat/completions
+  LLM_MODEL: Qwen/Qwen2.5-32B-Instruct
+  LLM_TIMEOUT_MS: "60000"
+  LPT_AI-SERVICE_URL: http://lpt-ai:5199
+  PORT: "5199"
+
+  # Spring Boot Database
+  SPRING_DATASOURCE_URL: jdbc:mysql://mysql:3306/learning_progress_tracker?allowPublicKeyRetrieval=true&characterEncoding=utf-8&useSSL=false&serverTimezone=GMT%2B8