fix: apply agent scheduling to every pod pool - #656

Ref PRO-6996 — https://linear.app/phaselaw/issue/PRO-6996

Description

• Apply the deployment's agent node selector and tolerations to standalone Jobs, bare workflow pods and persistent agents. These pools previously ignored the settings and could run outside a configured agent node pool.
• Share the existing repository scheduling parser across pool builders and preserve repository behavior. Malformed JSON prevents pod creation.
• Required before https://github.com/phaselabinc/infra/pull/2232; release this fix before updating its chart/image pins. Isolate existing HTTP unit tests from local services and wait for asynchronous cancellation messages in integration tests.

Testing

• 87 focused scheduling/pool/Kubernetes workload tests, 46 HTTP tests and all 18 local-run integration tests passed. The full pre-push suite passed all 13 tasks, including 2,985 API tests.
• Pre-commit lint, format and workspace typechecks passed. Tests cover bare workflow pods, Jobs and persistent agents using deployment scheduling.
• Live Kubernetes scheduling was not tested: this machine has production contexts only. Independent defect and simplification reviews found no remaining issues; all 13 CI checks passed.