Goal

Apply cross-cutting visual shell cleanup only after behavioral areas have stabilized, so visual polish does not need to be re-done while core surfaces are still moving.

Scope

In scope:

• Theme tokens.
• Bubble hairline outlines.
• Spacing scale.
• Typography for prose, reasoning, and tool output.
• Trow chevron sizing and direction.
• Animation timing such as expand/collapse and thinking indicator timing.

Out of scope:

• Final shell assembly from [Task] UI rewrite v2 Area E2: final shell modular rollout #606.
• New behavior changes in Areas A-D.

Relevant files or context

Parent: #599

Start condition:

• E1 starts only after at least 2 of Areas A-D have shipped their first behavioral PR.

Constraints:

• Visual shell work must still pass [Task] UI rewrite v2 PR0: perf-gated regression CI #600.
• No rework of already-delivered surfaces unless the visual shell change is intentional and measured.

Verification

• Every Area E1 PR passes [Task] UI rewrite v2 PR0: perf-gated regression CI #600.
• The 5-minute visual pass in docs/design/session-view-w1-manual-checklist.md passes.
• The PR clearly states which visual shell tokens or styles moved and which surfaces were re-measured.

Execution mode

Agent should investigate and propose a plan first