Add job processing system with streaming endpoint

Introduced a `processing` router to handle job streaming using server-sent events. Added `Jobs` and `JobStatus` models for managing job-related data, along with database creation logic. Updated the `sample` router to create new job entries during experiment creation.

backend/app/routers/sample.py

@@ -28,6 +28,8 @@ from app.models import (
     ExperimentParameters as ExperimentParametersModel,
     # ExperimentParameters,
     Results as ResultsModel,
+    Jobs as JobModel,
+    JobStatus,
 )
 from app.dependencies import get_db
 import logging
@@ -348,6 +350,15 @@ def create_experiment_parameters_for_sample(
     db.add(new_event)
     db.commit()
 
+    new_job = JobModel(
+        experiment_parameters_id=new_exp.id,  # <-- Correct reference here
+        parameters=new_exp.to_dict(),  # assuming params has a to_dict() method
+        status=JobStatus.TODO,
+    )
+    db.add(new_job)
+    db.commit()
+    db.refresh(new_job)
+
     return new_exp