Adopt #9106 tool group summaries: mobile work-log needs an architectural merge

[rynfar]

#9106 (b520120cf169ce63a5606447a292451e97622c9a, 27 files) is the largest
remaining commit from the 2026-09-03 upstream batch and the hub that gates at
least two others. Seven of its eight conflicted files are already resolved
and saved at /tmp/pylon-9106/ (see below). One file needs real design work.

The blocker

apps/mobile/src/features/threads/thread-work-log.tsx — Pylon 567 lines,
upstream 1055. #9106 does not modify this component, it replaces its
architecture:

Upstream introduces	Pylon has
ThreadWorkGroupList with scroll anchoring	flat View list
resolveWorkGroupScrollAnchor, shouldFollowThreadWorkGroupAppend	—
WorkLogIcon wrapper	direct SymbolView with tintColorClassName
THREAD_WORK_ROW_MIN_HEIGHT, workLogRowsHeight(activities, rowHeight)	WORK_ROW_HEIGHT = 32, collapsedWorkLogHeight()
renderImage: MarkdownImageRenderer, onToggleRow(rowId, anchorKey)	onToggleRow(rowId), compactActivityDetail

The largest conflict region is 141 lines of Pylon rendering against 13 lines of
upstream's new component call.

This must not be rushed. AGENTS.md names this file as the reference for
gated animation — "an unbounded animation that survives all three gates pegs
the GPU on high-refresh displays". Pylon's shimmer gate here is deliberate and
is exactly what an architectural port is most likely to drop.

Already resolved (restore over the conflicted files after re-picking)

• apps/mobile/src/lib/threadActivity.ts — took upstream's active/live
  shape. latestActiveActivity already encodes Pylon's gate (isWorking &&
  unsettled turn && inProgress), so upstream's shimmer: active preserves
  Pylon's shimmer discipline rather than loosening it.
• apps/mobile/src/lib/threadActivity.test.ts — upstream rewrote the
  "respects the %s lifecycle of trailing task progress" body to a single
  shimmer assertion; Pylon's other tests in that block are kept.
• apps/web/src/components/chat/MessagesTimeline.tsx — six regions. Kept
  Pylon's groupLabel/GroupContainer aria wrapper, missingResponse /
  turnSettled / neutral+success indicators, and the chevron/failed block.
  Took upstream's icon rendering (Pylon's WorkEntryIconSvg and
  showEntryIcon no longer exist after the commit's clean hunks) and its
  richer canExpand. Renamed isExpandedToolGroupEntry -> isExpandedToolGroup.
• apps/web/src/components/chat/MessagesTimeline.logic.ts — #9106 moves
  normalizeCompactToolLabel, toolGroupAction, workLogEntryIsLocalCodeSearch,
  summarizeToolGroup, omitSupersededLifecycleMarkers, toolGroupSummaryKind
  and the ToolGroupSummaryKind type into client-runtime. Pylon's local copies
  were verified identical apart from WorkLogEntry vs WorkLogPresentationEntry
  and removed.
• apps/web/src/components/sidebar/SidebarChrome.tsx — Pylon-first: upstream
  reverts to T3Wordmark, Pylon keeps PylonMark. Never restore T3 branding.
• packages/client-runtime/src/work-log/presentation.ts — union of Pylon's
  detail? and upstream's toolData?.
• packages/client-runtime/package.json — union of Pylon's ./rollback and
  upstream's ./work-log/scroll-anchor export.

Web typechecks clean with these applied; only the mobile file remains.

Unblocks

• #9172 8339508f5c align failed task progress test
• #9359 24799de4f8 size expanded tool groups correctly

Both were confirmed chained on this commit.

Context

• Batch-1 (merged): upstream: adopt the clean half of the 2026-09-03 T3 batch (65 commits) #260 · Batch-2 (merged): upstream: adopt the 2026-09-03 T3 batch, pass two (in progress) #261
• Antigravity, held separately: Adopt upstream Antigravity provider (#9348) without regressing Prime Agent #262
• Review ledger: .agents/upstream-review.md