feat(inbox): render the signal report artefact log

[oliverb123]

Problem

Signal reports now accumulate a richer set of artefacts on the backend — code references, diffs, pushed branches, task runs, and notes — alongside the existing judgments and findings. The inbox had no way to surface them, so all that work-log context was invisible to reviewers.

This is the PostHog Code side of the artefact-log feature. The backend half (new artefact types, the append-only log, the pushed_branch diff endpoint, and the task_run (product, type) model) lands in PostHog/posthog#61545.

Changes

Adds a chronological artefact log at the bottom of the report detail pane, rendering every artefact type with a tailored body rather than raw JSON:

• Code references / line references — syntax-highlighted code blocks with the relevant span and note.
• Code diffs — unified-diff rendering with add/remove coloring (DiffBlock).
• Pushed branches — metadata always shown, with a collapsible "View diff" that fetches the branch-vs-base diff on demand from the new backend endpoint; missing/deleted branches surface a clean message instead of a raw error.
• Task runs — loads the linked task and expands to its full conversation log via TaskLogsPanel. Badged from the artefact's (product, type): signals-pipeline runs show Research / Implementation; custom agents show their humanized product + type.
• Notes / judgments / findings / reviewers — each rendered as a point-in-time entry with a relative timestamp.
• A dev-only raw-JSON inspector on each row (hidden in release builds, same pattern as other dev-only controls).

Artefact content types are hand-written in shared/types.ts and normalized in posthogClient.ts (the task_run content carries product/type, matching the backend).

How did you test this?

• pnpm typecheck — passes.
• biome check — clean on all changed files.
• Manual: rendered a report seeded with one of each artefact type against a local backend; verified the pushed_branch diff loads against a real pushed branch, the task_run entry expands to the conversation log, and the timeline orders correctly by timestamp.
• No automated component tests were added for these renderers.

Automatic notifications

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

---

Created with PostHog Code

[github-actions]

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

2 warnings

src/renderer/features/inbox/components/detail/ArtefactLogList.tsx

• ⚠️ src/renderer/features/inbox/components/detail/ArtefactLogList.tsx:363 Spread copy before sort() js-tosorted-immutable

src/renderer/features/inbox/components/detail/ReportDetailPane.tsx

• ⚠️ src/renderer/features/inbox/components/detail/ReportDetailPane.tsx:260 Missing effect dependencies exhaustive-deps

_{Reviewed by React Doctor for commit 2ad6d0e.}

[greptile-apps]

Comments Outside Diff (1)

1. apps/code/src/renderer/features/inbox/components/detail/ArtefactTaskRun.tsx, line 814-819 (link)

   Eager task fetches vs. lazy diff fetches

   ArtefactPushedBranch only fetches the diff when the user expands the row (enabled: expanded), but ArtefactTaskRun fires getTask immediately on mount regardless of whether the row is expanded. In a report with many task_run artefacts this generates N simultaneous API calls as soon as the detail pane opens. The task title displayed in the collapsed state is the only reason for eager loading, but content.task_id could be used as the fallback text (it already is, on line 851) until the user expands the row, which would allow lazy loading here too.

   Prompt To Fix With AI

   This is a comment left during a code review.
   Path: apps/code/src/renderer/features/inbox/components/detail/ArtefactTaskRun.tsx
   Line: 814-819
   
   Comment:
   **Eager task fetches vs. lazy diff fetches**
   
   `ArtefactPushedBranch` only fetches the diff when the user expands the row (`enabled: expanded`), but `ArtefactTaskRun` fires `getTask` immediately on mount regardless of whether the row is expanded. In a report with many `task_run` artefacts this generates N simultaneous API calls as soon as the detail pane opens. The task title displayed in the collapsed state is the only reason for eager loading, but `content.task_id` could be used as the fallback text (it already is, on line 851) until the user expands the row, which would allow lazy loading here too.
   
   How can I resolve this? If you propose a fix, please make it concise.

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
apps/code/src/renderer/features/inbox/components/detail/ArtefactTaskRun.tsx:814-819
**Eager task fetches vs. lazy diff fetches**

`ArtefactPushedBranch` only fetches the diff when the user expands the row (`enabled: expanded`), but `ArtefactTaskRun` fires `getTask` immediately on mount regardless of whether the row is expanded. In a report with many `task_run` artefacts this generates N simultaneous API calls as soon as the detail pane opens. The task title displayed in the collapsed state is the only reason for eager loading, but `content.task_id` could be used as the fallback text (it already is, on line 851) until the user expands the row, which would allow lazy loading here too.

### Issue 2 of 2
apps/code/src/renderer/features/inbox/components/detail/ArtefactTaskRun.tsx:37-38
`getTask` already returns `Task` internally (it does its own `as unknown as Task` cast). The additional cast here is redundant and suggests a type mismatch that isn't actually present. Removing the outer cast makes the intent clear.

```suggestion
    (client) => client.getTask(content.task_id),
```

_{Reviews (1): Last reviewed commit: "feat(inbox): render the signal report ar..." | Re-trigger Greptile}

[greptile-apps]

getTask already returns Task internally (it does its own as unknown as Task cast). The additional cast here is redundant and suggests a type mismatch that isn't actually present. Removing the outer cast makes the intent clear.

Suggested change

	async (client) =>
	(await client.getTask(content.task_id)) as unknown as Task,
	(client) => client.getTask(content.task_id),

Prompt To Fix With AI

This is a comment left during a code review.
Path: apps/code/src/renderer/features/inbox/components/detail/ArtefactTaskRun.tsx
Line: 37-38

Comment:
`getTask` already returns `Task` internally (it does its own `as unknown as Task` cast). The additional cast here is redundant and suggests a type mismatch that isn't actually present. Removing the outer cast makes the intent clear.

```suggestion
    (client) => client.getTask(content.task_id),
```

How can I resolve this? If you propose a fix, please make it concise.

Note: If this suggestion doesn't match your team's coding style, reply to this and let me know. I'll remember it for next time!