refactor(core): rename cloud task service as engine

[richardsolomou]

Problem

The cloud-task implementation needs to become a reusable engine, but keeping cloud-task.ts as a wrapper in the same diff prevents GitHub from showing the implementation move.

Depends on #3623
Refs PostHog/posthog#76229

Changes

Phase 1 only: I renamed cloud-task.ts to cloud-task-engine.ts byte-for-byte and updated imports. GitHub shows this as a 100% rename; the engine refactor and wrapper are deferred to the next PR.

How did you test this?

• Full monorepo typecheck at this checkpoint
• Final stack: 711 shared, 153 API-client, 2,599 core, and 451 mobile tests

Automatic notifications

• Publish to changelog?
• Alert Sales and Marketing teams?

---

Created with PostHog Code

[github-actions]

React Doctor found no issues in the changed files. 🎉

_{Reviewed by React Doctor for commit d4c7d62.}

[richardsolomou]

• feat(mobile): add Codex task parity #3654
• refactor(mobile): finalize portability boundary #3642
• refactor(mobile): adopt shared interaction semantics #3641
• refactor(mobile): finish shared task and inbox adoption #3640
• refactor(mobile): adopt shared task runtime #3637
• refactor(core): extract shared presentation semantics #3635
• refactor(core): extract permission and composer semantics #3634
• refactor(core): extract repository integration semantics #3633
• refactor(core): extract portable cloud task engine #3608
• refactor(core): rename cloud task service as engine #3624 👈 (View in Graphite)
• refactor(core): extract cloud task policies #3623
• refactor(api-client): extract cloud task transport #3622
• refactor(shared): extract task contracts and model policy #3616
• main

This stack of pull requests is managed by Graphite. Learn more about stacking.

[greptile-apps]

Prompt To Fix All With AI

Fix the following 2 code review issues. Work through them one at a time, proposing concise fixes.

---

### Issue 1 of 2
packages/core/src/cloud-task/cloud-task-engine.ts:2165
**Archived fetch can hang hydration**

When a terminal run has no persisted session-log rows and its archive request stalls, this unbounded fetch never emits a snapshot or retryable error, leaving the mobile task session loading indefinitely.

### Issue 2 of 2
packages/core/src/cloud-task/cloud-task-engine.ts:2169-2170
**Malformed line discards entire archive**

When an archived NDJSON log contains one malformed line, parsing the complete array throws and returns `null`, causing hydration to reject every otherwise valid entry; the previous mobile parser skipped malformed lines and retained the remaining task history.

_{Reviews (1): Last reviewed commit: "fix(core): restore archived cloud task l..." | Re-trigger Greptile}

[veria-ai]

PR overview

All previously flagged issues have been addressed. No open security concerns remain on this pull request.

Security review

No open security issues remain on this pull request.

Fixed/addressed: 1 · PR risk: 0/10

[trunk-io]

😎 Merged successfully - details.