fix(observatory): version non-binding idle claims and preserve grant history

src/k1link/web/observatory_worker_api.py

@@ -158,7 +158,10 @@ class ObservatoryWorkerExecutorCapability(_StrictWorkerRequest):
 
 
 class ObservatoryWorkerClaimRequest(_StrictWorkerRequest):
-    schema_version: Literal["missioncore.observatory-worker-claim-request/v2"]
+    schema_version: Literal[
+        "missioncore.observatory-worker-claim-request/v2",
+        "missioncore.observatory-worker-claim-request/v3",
+    ]
     claim_request_id: str = Field(
         min_length=1,
         max_length=160,
@@ -276,6 +279,10 @@ def build_observatory_worker_router(
         dependencies=[Depends(require_configured_worker)],
     )
 
+    @router.get("/recorded-jobs/claim-readiness")
+    def claim_readiness() -> dict[str, object]:
+        return _queue_call(queue.claim_readiness)
+
     @router.post("/recorded-jobs/claims", response_model=None)
     def claim_next(
         request: ObservatoryWorkerClaimRequest,
@@ -288,10 +295,15 @@ def build_observatory_worker_router(
                     capability.recorded_identity()
                     for capability in request.supported_executor_identities
                 ),
+                protocol_version=(3 if request.schema_version.endswith("/v3") else 2),
             )
         )
         if claim is None:
-            return Response(status_code=204)
+            return Response(status_code=204, headers={
+                "X-Mission-Core-Idle-Claim": (
+                    "non-binding" if request.schema_version.endswith("/v3") else "durable"
+                ),
+            })
         return claim.as_dict()
 
     @router.get("/recorded-jobs/{job_id}")