Add minimal FastAPI app

app.py

@@ -0,0 +1,15 @@
+from fastapi import FastAPI
+
+app = FastAPI(title="Eroha Minimal Health Test")
+
+@app.get("/")
+def home():
+    return {"message": "Hello, Eroha — this is a minimal FastAPI test!"}
+
+@app.get("/check")
+def check_health():
+    return {
+        "status": "ok",
+        "modules": ["core", "rag", "metrics"],
+        "version": "test-1.0"
+    }