feat(web): show the owner's avatar on sessions someone else started

[tusharbhardwaj-bk]

Problem

In a shared environment the experimental sidebar mixes my own sessions with the ones teammates started and tagged me into, and the rows look identical. Whose session a row is was only discoverable by opening the thread.

Fix

Thread rows now carry the owner's avatar immediately left of the provider icon, in the same bottom-right lane as the priority badge — but only when the owner is someone other than the current operator. My own face on every row of my own sidebar would carry no information.

Nothing renders when:

• the thread is unowned (ownerUserId === null — single-user mode, or awaiting backfill), or
• there is no team identity for the operator (every row would otherwise light up), or
• the operator is the owner.

So this is a no-op outside team mode.

Shape of the change:

• phaseSidebarRowOwnerAvatarUserId in PhaseGroupedSidebar.logic.ts — the pure "whose face, if anyone's" decision, unit-tested.
• sidebar/PhaseSidebarOwnerAvatar.tsx — new fork-owned component, split into a presentational view (asserted with static markup) and a thin connected wrapper. Rendered only when the helper returns a user id, so rows that need no avatar never subscribe to the org directory and the memo'd row keeps comparing by value.
• One guarded element at the row call site. Departed or not-yet-loaded members fall back to initials via resolveUser, so a row never shows a hole.

Verification

• vp test run on the two touched test files — 82 passed.
• tsgo --noEmit for @t3tools/web — clean.
• vp lint and vp fmt on the changed files — clean.
• node scripts/check-fork-markers.ts — passed.

No before/after images: capturing them needs a browser session on the shared dev server, which was not authorised for this change. The rendered result is verified on expbkt3 after deploy, which is what this branch targets.

🤖 Generated with Claude Code

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[github-actions]

Thread transfer impact

✅ Thread transfer remains within every enforced ceiling.

ℹ️ No successful main baseline artifact is available yet. This run establishes the initial measurement.

Provider	Metric	Main baseline	This PR	Impact	PR ceiling
Codex	Total thread wire	—	11.5 KiB	—	15.1 KiB	✅
Codex	Thread snapshot wire	—	5.7 KiB	—	7.3 KiB	✅
Codex	Live turn WebSocket wire	—	5.7 KiB	—	7.8 KiB	✅
Codex	Live turn WebSocket decoded	—	50.4 KiB	—	66.4 KiB	✅
Codex	Live turn messages	—	11	—	21	✅
Claude	Total thread wire	—	11.4 KiB	—	15.1 KiB	✅
Claude	Thread snapshot wire	—	5.7 KiB	—	7.3 KiB	✅
Claude	Live turn WebSocket wire	—	5.7 KiB	—	7.8 KiB	✅
Claude	Live turn WebSocket decoded	—	51.2 KiB	—	66.4 KiB	✅
Claude	Live turn messages	—	11	—	21	✅

Baseline: unavailable · PR result: 81842e7 · Source CI: success

Scenario and decoded snapshot size

10 historical turns, 5 command tools per turn, 878.9 KiB retained MCP result per historical turn, and a 1.05 MiB retained result in the measured turn.

• Codex decoded thread snapshot: 95.6 KiB
• Claude decoded thread snapshot: 96.3 KiB

Updated in place by a trusted workflow. PR artifacts are strictly validated and never executed.