Add Pydantic models and FastAPI router structure for agent and backend

backend/app/routers/jobs.py

@@ -0,0 +1,19 @@
+from fastapi import APIRouter, HTTPException
+
+from app.schemas import EntityResponse, Job, ListResponse
+from app.services.store import JOBS
+
+router = APIRouter(prefix='/jobs', tags=['jobs'])
+
+
+@router.get('', response_model=ListResponse[Job])
+def list_jobs() -> ListResponse[Job]:
+    return ListResponse(count=len(JOBS), items=JOBS)
+
+
+@router.get('/{job_id}', response_model=EntityResponse[Job])
+def get_job(job_id: str) -> EntityResponse[Job]:
+    for item in JOBS:
+        if item.id == job_id:
+            return EntityResponse(item=item)
+    raise HTTPException(status_code=404, detail='Job not found')