fix: expose OpenEnv endpoints on port 7860 to satisfy hackathon validator

Dockerfile

@@ -45,5 +45,5 @@ EXPOSE 7860
 # Set production mode at runtime only (not at build time)
 ENV NODE_ENV=production
 
-# Run backend + frontend
-CMD ["sh", "-c", "uvicorn backend.app.main:app --host 127.0.0.1 --port 8000 2>/dev/null & cd /app/lifeline-ai && exec npm run start -- -p 7860"]
+# Run backend as the primary app for OpenEnv validation
+CMD ["uvicorn", "backend.app.main:app", "--host", "0.0.0.0", "--port", "7860"]

backend/app/main.py

@@ -7,15 +7,24 @@ from typing import Any, Dict, List, Optional
 from fastapi import FastAPI, HTTPException
 from pydantic import BaseModel
 
+import sys
+# Ensure project root is in path for environment and models
+sys.path.append(os.getcwd())
+
+from environment import MediRouteEnv
+from models import Action, Observation, StepResult
+
 # Import the existing inference runner so we can reuse run_episode
 try:
-    # inference.py lives at project root and exports run_episode
     import inference
 except Exception:
     inference = None
 
 app = FastAPI(title="LifeLine AI API", version="1.0.0")
 
+# Global environment instance for the OpenEnv validator
+env = MediRouteEnv()
+
 # Configure logging for startup visibility
 logger = logging.getLogger("lifeline.backend")
 logging.basicConfig(level=logging.INFO)
@@ -46,6 +55,41 @@ def health() -> Dict[str, str]:
     return {"status": "ok", "project": "LifeLine AI"}
 
 
+# ── OpenEnv Endpoints ──────────────────────────────────────────────────────
+
+class ResetRequest(BaseModel):
+    difficulty: str = "easy"
+
+
+@app.post("/reset")
+async def reset(req: ResetRequest = ResetRequest()) -> Observation:
+    """Reset the environment to a fresh state with the given difficulty."""
+    logger.info(f"OpenEnv: resetting to difficulty={req.difficulty}")
+    obs = env.reset(difficulty=req.difficulty)
+    return obs
+
+
+@app.post("/step")
+async def step(action: Action) -> StepResult:
+    """Advance the environment by one step using the provided action."""
+    logger.info(f"OpenEnv: step with action={action.action_type}")
+    try:
+        result = env.step(action)
+        return result
+    except Exception as e:
+        logger.error(f"OpenEnv step failed: {e}")
+        raise HTTPException(status_code=500, detail=str(e))
+
+
+@app.get("/state")
+async def get_state() -> Observation:
+    """Return the current snapshot of the environment's observation."""
+    try:
+        return env.state()
+    except Exception as e:
+        raise HTTPException(status_code=400, detail=str(e))
+
+
 @app.post("/run-benchmark")
 def run_benchmark(req: BenchmarkRequest) -> Dict[str, Any]:
     """Run the existing inference benchmark and return structured JSON results.