[codex] Harden dashboard run activity charts (#4126)

## Thinking Path

> - Paperclip gives operators a live view of agent work across
dashboards, transcripts, and run activity charts
> - Those views consume live run updates and aggregate run activity from
backend dashboard data
> - Missing or partial run data could make charts brittle, and live
transcript updates were heavier than needed
> - Operators need dashboard data to stay stable even when recent run
payloads are incomplete
> - This pull request hardens dashboard run aggregation, guards chart
rendering, and lightens live run update handling
> - The benefit is a more reliable dashboard during active agent
execution

## What Changed

- Added dashboard run activity types and backend aggregation coverage.
- Guarded activity chart rendering when run data is missing or partial.
- Reduced live transcript update churn in active agent and run chat
surfaces.
- Fixed issue chat avatar alignment in the thread renderer.
- Added focused dashboard, activity chart, and live transcript tests.

## Verification

- `pnpm install --frozen-lockfile --ignore-scripts`
- `pnpm exec vitest run server/src/__tests__/dashboard-service.test.ts
ui/src/components/ActivityCharts.test.tsx
ui/src/components/transcript/useLiveRunTranscripts.test.tsx`
- Result: 8 tests passed, 1 skipped. The embedded Postgres dashboard
service test skipped on this host with the existing PGlite/Postgres init
warning; UI chart and transcript tests passed.

## Risks

- Medium-low risk: aggregation semantics changed, but the UI remains
guarded around incomplete data.
- The dashboard service test is host-skipped here, so CI should confirm
the embedded database path.

> For core feature work, check [`ROADMAP.md`](ROADMAP.md) first and
discuss it in `#dev` before opening the PR. Feature PRs that overlap
with planned core work may need to be redirected — check the roadmap
first. See `CONTRIBUTING.md`.

## Model Used

- OpenAI Codex coding agent based on GPT-5, tool-enabled local shell and
GitHub workflow, exact runtime context window not exposed in this
session.

## Checklist

- [x] I have included a thinking path that traces from project context
to this change
- [x] I have specified the model used (with version and capability
details)
- [x] I have checked ROADMAP.md and confirmed this PR does not duplicate
planned core work
- [x] I have run tests locally and they pass
- [x] I have added or updated tests where applicable
- [x] If this change affects the UI, I have included before/after
screenshots, or documented why targeted component tests are sufficient
here
- [x] I have updated relevant documentation to reflect my changes
- [x] I have considered and documented any risks above
- [x] I will address all Greptile and reviewer comments before
requesting merge

---------

Co-authored-by: Paperclip <noreply@paperclip.ing>

ui/src/components/RunChatSurface.tsx

@@ -1,9 +1,15 @@
-import { useMemo } from "react";
+import { memo, useMemo } from "react";
 import type { TranscriptEntry } from "../adapters";
 import type { LiveRunForIssue } from "../api/heartbeats";
 import { IssueChatThread } from "./IssueChatThread";
 import type { IssueChatLinkedRun } from "../lib/issue-chat-messages";
 
+const EMPTY_COMMENTS: [] = [];
+const EMPTY_TIMELINE_EVENTS: [] = [];
+const EMPTY_LIVE_RUNS: [] = [];
+const EMPTY_LINKED_RUNS: [] = [];
+const handleEmbeddedAdd = async () => {};
+
 function isRunActive(run: LiveRunForIssue) {
   return run.status === "queued" || run.status === "running";
 }
@@ -15,18 +21,18 @@ interface RunChatSurfaceProps {
   companyId?: string | null;
 }
 
-export function RunChatSurface({
+export const RunChatSurface = memo(function RunChatSurface({
   run,
   transcript,
   hasOutput,
   companyId,
 }: RunChatSurfaceProps) {
   const active = isRunActive(run);
-  const liveRuns = active ? [run] : [];
+  const liveRuns = useMemo(() => (active ? [run] : EMPTY_LIVE_RUNS), [active, run]);
   const linkedRuns = useMemo<IssueChatLinkedRun[]>(
     () =>
       active
-        ? []
+        ? EMPTY_LINKED_RUNS
         : [{
             runId: run.id,
             status: run.status,
@@ -45,12 +51,12 @@ export function RunChatSurface({
 
   return (
     <IssueChatThread
-      comments={[]}
+      comments={EMPTY_COMMENTS}
       linkedRuns={linkedRuns}
-      timelineEvents={[]}
+      timelineEvents={EMPTY_TIMELINE_EVENTS}
       liveRuns={liveRuns}
       companyId={companyId}
-      onAdd={async () => {}}
+      onAdd={handleEmbeddedAdd}
       showComposer={false}
       showJumpToLatest={false}
       variant="embedded"
@@ -61,4 +67,4 @@ export function RunChatSurface({
       includeSucceededRunsWithoutOutput
     />
   );
-}
+});