fix(web): restore composer stage artwork

[t3-code]

What Changed

• restores the Dev and Nightly artwork inside the composer send button
• adds compact artwork crops sized for the action button
• limits the fixed-color treatment to the default T3 Code theme so palette themes keep their safe themed button

Why

The composer artwork was removed when theme colors replaced it. This restores the original T3 Code treatment without introducing contrast issues in custom themes.

UI Changes

Before	After

Validation

• vp test run apps/web/src/hooks/useSettings.test.ts apps/web/src/components/SidebarStageBackdrop.test.tsx apps/web/src/components/chat/ComposerPrimaryActions.test.ts (24 passed)
• vp run --filter @t3tools/web typecheck
• vp run lint (0 errors, one unrelated existing warning)
• git diff --check

Checklist

• tested locally
• added regression coverage
• included before/after UI evidence

---

Note

Low Risk
Composer send-button styling and theme gating only; no auth, data, or API changes, with regression tests added.

Overview
Brings back Dev and Nightly stage artwork on the composer send button when environment identification is set to artwork and the app is on the default (non-palette) theme.

Adds StageBackdropButtonArt and a compact viewBox on the existing nightly/dev SVGs so the art fits the circular action button. The send control switches to a transparent background with the artwork behind the icon; busy/disabled aria-label behavior is unchanged.

Introduces useDefaultEnvironmentArtworkEnabled (refactors shared theme checks in useSettings) so fixed-color stage art is not used under custom palette themes, avoiding contrast clashes outside the sidebar.

^{Reviewed by Cursor Bugbot for commit 4a5eae5. Bugbot is set up for automated code reviews on this repo. Configure here.}

Note

Restore stage artwork to the composer send button

• Adds StageBackdropButtonArt to SidebarStageBackdrop.tsx, a compact (96×96 viewBox) variant of the existing NightlySkyArt/DevBlueprintArt components.
• Updates ComposerPrimaryActions.tsx to render StageBackdropButtonArt as a background on the send button when default environment artwork is enabled and a stage variant resolves; otherwise the button is unchanged.
• Adds useDefaultEnvironmentArtworkEnabled to useSettings.ts, which returns true only when client settings are hydrated, the environment identification mode is 'artwork', and no palette theme is active.

^{Macroscope summarized 4a5eae5.}

[github-actions]

Thread transfer impact

✅ Thread transfer remains within every enforced ceiling.

Provider	Metric	Main baseline	This PR	Impact	PR ceiling
Codex	Total thread wire	11.3 KiB	11.3 KiB	−11 B (−0.1%)	15.1 KiB	✅
Codex	Thread snapshot wire	5.5 KiB	5.5 KiB	0 B (0.0%)	7.3 KiB	✅
Codex	Live turn WebSocket wire	5.9 KiB	5.9 KiB	−11 B (−0.2%)	7.8 KiB	✅
Codex	Live turn WebSocket decoded	49.7 KiB	49.7 KiB	0 B (0.0%)	66.4 KiB	✅
Codex	Live turn messages	16	16	0 (0.0%)	21	✅
Claude	Total thread wire	11.3 KiB	11.3 KiB	+4 B (+0.0%)	15.1 KiB	✅
Claude	Thread snapshot wire	5.5 KiB	5.5 KiB	−5 B (−0.1%)	7.3 KiB	✅
Claude	Live turn WebSocket wire	5.8 KiB	5.9 KiB	+9 B (+0.2%)	7.8 KiB	✅
Claude	Live turn WebSocket decoded	50.6 KiB	50.6 KiB	0 B (0.0%)	66.4 KiB	✅
Claude	Live turn messages	16	16	0 (0.0%)	21	✅

Baseline: ac4780f · PR result: 4a5eae5 · 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: 94.6 KiB
• Claude decoded thread snapshot: 95.4 KiB

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

[macroscopeapp]

Approvability

Verdict: Approved 4a5eae5

This is a small UI bug fix that restores artwork styling to the composer send button. Changes are limited to visual components with a simple conditional rendering approach, backed by comprehensive tests.

^{You can customize Macroscope's approvability policy. Learn more.}

[t3dotgg]

Note

🤖 GPT-5.6 Sol responding on behalf of Theo

We're closing this PR as we clean up the T3 Code backlog. Thank you for taking the time to put this together.

The primary composer artwork restoration landed in #6183. This branch still adds a different all-palette disable rule, while main keeps built-in theme-aware artwork and only suppresses unsupported user palettes, so we are not taking the remaining policy change.

If you believe we closed this in error, please reopen the PR and leave a comment explaining what we missed.