fix(cron): use job config for cleanup instead of hardcoded "keep" (openclaw#15427) thanks @arosstale

Verified:
- pnpm install --frozen-lockfile
- pnpm build
- pnpm check
- pnpm test

Co-authored-by: arosstale <117890364+arosstale@users.noreply.github.com>
Co-authored-by: Tak Hoffman <781889+Takhoffman@users.noreply.github.com>

CHANGELOG.md

@@ -50,6 +50,7 @@ Docs: https://docs.openclaw.ai
 - Onboarding/CLI: restore terminal state without resuming paused `stdin`, so onboarding exits cleanly after choosing Web UI and the installer returns instead of appearing stuck.
 - Auth/OpenAI Codex: share OAuth login handling across onboarding and `models auth login --provider openai-codex`, keep onboarding alive when OAuth fails, and surface a direct OAuth help note instead of terminating the wizard. (#15406, follow-up to #14552) Thanks @zhiluo20.
 - Cron: add regression coverage for announce-mode isolated jobs so runs that already report `delivered: true` do not enqueue duplicate main-session relays, including delivery configs where `mode` is omitted and defaults to announce. (#15737) Thanks @brandonwise.
+- Cron: honor `deleteAfterRun` in isolated announce delivery by mapping it to subagent announce cleanup mode, so cron run sessions configured for deletion are removed after completion. (#15368) Thanks @arosstale.
 - Onboarding/Providers: add vLLM as an onboarding provider with model discovery, auth profile wiring, and non-interactive auth-choice validation. (#12577) Thanks @gejifeng.
 - Onboarding/Providers: preserve Hugging Face auth intent in auth-choice remapping (`tokenProvider=huggingface` with `authChoice=apiKey`) and skip env-override prompts when an explicit token is provided. (#13472) Thanks @Josephrp.
 - OpenAI Codex/Spark: implement end-to-end `gpt-5.3-codex-spark` support across fallback/thinking/model resolution and `models list` forward-compat visibility. (#14990, #15174) Thanks @L-U-C-K-Y, @loiie45e.