update the codebase poc ver1

secrets_template/gemini_api_key.txt

@@ -0,0 +1,14 @@
+# Gemini API Key Reference
+# This file documents the secret reference for the Gemini API key used by the Cloud LLM Gateway.
+#
+# Production secret location: GCP Secret Manager
+# Secret name: gemini-api-key
+# Project: vkist-project
+# Region: asia-southeast1
+#
+# Access pattern:
+#   FastAPI Cloud LLM Gateway fetches key from GCP Secret Manager at startup
+#   Key never written to disk; accessed via GCP Workload Identity or service account
+#
+# Fallback: modal.Secret.from_name("gcp-secrets") in Modal deployment
+#           allows MedGemma container to authenticate to GCP Vertex AI if needed.