docs(priorities): refresh planner queue for 3829

[asim]

Summary:

• Replace closed Stabilize file-store suffix expiry test timing #3780 with Stabilize atlascloud plan-delegate harness timeout #3826 as the top planner queue item after the file-store timing blocker shipped.
• Keep cancellation/deadline propagation, OTel run spans, and AP2 mandate support ordered behind the live harness timeout by roadmap value.

Testing:

• go build ./...
• go test ./... (fails in this environment: loopback targets forbidden for grpc loopback tests)
• golangci-lint run ./...

Closes #3829