fix(desktop): keep task startup in loading state

[adamleithp]

Problem

People see several infrastructure states while a task starts, which makes normal startup look stalled or inactive.

Setup logs can also replace the startup spinner before the agent starts the first prompt.

Changes

• Task creation, worktree setup, queueing, sandbox setup, and connection setup now show a spinner with Loading.
• Setup logs keep the loading state active until the active run sends its first prompt.
• A failed run replaces the spinner with a red Failed status.
• The status marker uses the standard spinner instead of the dot-ring animation.
• Run-bound markers prevent old run updates from ending a successor run's loading state.
• Transcript hydration preserves the first-prompt state across window replacement and event eviction.

Before:

flowchart LR
    A[Submit task] --> B[Starting task]
    B --> C[Queue status]
    C --> D[Sandbox status]
    D --> E[Conversation]
    classDef phBlue fill:#1d4aff,stroke:#1d4aff,color:#fff;
    classDef phYellow fill:#f9bd2b,stroke:#f9bd2b,color:#000;
    class A,E phBlue;
    class B,C,D phYellow;

Loading

After:

flowchart LR
    A[Submit task] --> B[Loading]
    B --> C[First prompt]
    C --> D[Working]
    B --> E[Failed]
    classDef phBlue fill:#1d4aff,stroke:#1d4aff,color:#fff;
    classDef phRed fill:#f54e00,stroke:#f54e00,color:#fff;
    classDef phYellow fill:#f9bd2b,stroke:#f9bd2b,color:#000;
    class A,C,D phBlue;
    class B phYellow;
    class E phRed;

Loading

No screenshot: the local Electron app did not finish booting in this sandbox.

How did you test this code?

• The session tests cover fresh, resumed, stale, offline, failed, hydrated, evicted, and terminal runs.
• The UI tests cover Loading, Working, Failed, permissions, and standard spinner rendering.
• The thermo-nuclear code quality review approved the final transition model.
• pnpm typecheck
• Biome checks for the full Desktop workspace and packages/core
• node scripts/check-host-boundaries.mjs
• uv run ./bin/hogli ci:preflight --strict

👉 Stay up-to-date with PostHog coding conventions for a smoother review.

Automatic notifications

• Publish to changelog?

Docs update

No docs change. This change only affects transient task status text and icons.

🤖 Agent context

Autonomy: Human-driven (agent-assisted)

• The PostHog Desktop agent used independent review agents and repository file tools.
• Skills: /posthog-desktop, /writing-ui-components, /writing-user-facing-copy, /writing-tests, /writing-code-comments, /writing-simplified-technical-english, /qa-team, /dynamic-workflows, /running-ci-preflight, /test-electron-app, and /writing-pr-descriptions.
• The review found lifecycle races, and the final design uses one run-scoped core lifecycle model.
• The duplicate search found no open PR for this change.
• The public diff contains no private task material.

---

Created with PostHog Desktop

[trunk-io]

😎 Merged successfully - details.

[github-actions]

React Doctor found 2 issues in 2 files · 2 warnings.

2 warnings

packages/ui/src/features/sessions/components/SessionView.tsx

• ⚠️ packages/ui/src/features/sessions/components/SessionView.tsx:101 Non-component export in component file only-export-components

packages/ui/src/features/sidebar/components/items/TaskStatusDot.tsx

• ⚠️ packages/ui/src/features/sidebar/components/items/TaskStatusDot.tsx:131 Non-component export in component file only-export-components

_{Reviewed by React Doctor for commit a6add0f.}

[github-actions]

🤖 CI report

✅ Trunk lane — non-backend lane (fe:product:desktop)

This PR is assigned to the non-backend lane (fe:product:desktop). It does not run backend Python tests and may merge in parallel with PRs in other lanes.

[hosthog]

HostHog preview — posthog-desktop-web

The previews for this PR have been torn down and no longer serve.

[greptile-apps]

_{Reviews (1): Last reviewed commit: "Merge branch 'master' into posthog/optim..." | Re-trigger Greptile}

[stamphog]

Approved.

Contained UI/state-machine change to the desktop app's own task-status display (no auth, billing, migration, or CI surface), authored by a member of the owning team with extensive new/updated tests covering the added lifecycle edge cases, and no unresolved reviewer concerns.

• Author wrote 21% of the modified lines and has 53 merged PRs in these paths (familiarity MODERATE).
• 👍 on the PR from greptile-apps[bot].
• 27 of the 27 changed files are governed by products/desktop/AGENT_APPROVALS.md.

Gate mechanics and policy version

Gate		Result
prerequisites	✓	all clear
deny-list	✓	no deny categories matched
size	✓	577L, 17F substantive, 942L/27F incl. docs/generated/snapshots — within ceiling
tier	✓	T1-agent / T1d-complex (942L, 27F, single-area, fix)
stamphog 2.0.0b4		.stamphog/policy.yml @ a6add0f · reviewed head a6add0f

[deployment-status-posthog]

Deploy status

Environment	Status	Deployed At	Workflow
dev	✅ Deployed	2026-09-07 20:09 UTC	Run
prod-us	✅ Deployed	2026-09-07 20:22 UTC	Run
prod-eu	✅ Deployed	2026-09-07 20:28 UTC	Run