chore(upstream): adopt the 2026-08-16 T3 Code batch

[rynfar]

Upstream t3code-upstream/main moved ten commits past Pylon's review cursor. Nine are worth having and one points Windows users at a worse experience, so this branch adopts nine and skips one.

What landed

• #6663 tightens the themed-palette selector to html[data-theme-id]:not([data-theme-id=""]), closing the watch item left open by the 2026-08-15 batch.
• #7107 reworks the Advanced theme editor from ~60 raw color roles into named families, deriving paired foregrounds only for the family you touch so imported palettes survive editing.
• #6619 gives mobile the built-in theme library and System/Light/Dark selection, and moves the canonical palettes and preview generation into packages/shared so web and mobile cannot drift.
• #7132 stops a keyboard-highlighted command menu item from resting under the scroll-fade mask.
• #6267 and #7157 remove ~960 lines of duplicate and stale tests plus four test-only exports.
• #7171 replaces the CLAUDE.md symlink with an @AGENTS.md pointer file, which Windows checkouts cannot corrupt.
• #6392 truncates long commit-dialog paths from the start so the filename stays visible.
• #6635 lifts two Android thread-settings screens clear of the status bar.

Skipped: #7208, which drops the Windows-only silent-install warning from the update confirmation. Upstream's reason is that install times have improved — a claim about T3's pipeline, not Pylon's Windows builds. The warning describes real behavior (the app closes for minutes with no installer window), and without it Pylon reads as hung.

Pylon-first resolutions

• ProviderIcon.tsx — kept Pylon's Circle and providerIconKind provider marks while taking upstream's useAppearancePreferences.
• themePalette.ts — took upstream's file wholesale as the T3 Chat palettes move to packages/shared, then restored the three Pylon comment rebrands that survive the deletion.
• ProviderRegistry.test.ts — kept Pylon's rate-limit projection test, which sits immediately before the test upstream deletes.
• Branding on #6619 follows the F10 precedent: the mobile default theme id stays t3-code so saved preferences keep resolving, while its visible label, the new docs/user/mobile-appearance.md, and two doc comments became Pylon's.

pnpm-lock.yaml is untouched — packages/shared/package.json gains subpath exports only.

Verification

Typecheck clean across web, mobile, shared, t3, and desktop. vp fmt --check clean over 96 files. Tests: mobile 790/790, shared 10, server ProviderRegistry 52, scripts mobile-showcase 22, web 2,738/2,741.

The three web failures are in cloud/connectCliAuth.test.ts, which this branch does not touch, which fails in isolation, and which fails identically on a clean origin/pylon checkout. vite.config.ts assigns the repo's mapped VITE_ keys into process.env at module scope and Vite exposes them on import.meta.env, so the test reads a local .env that supplies T3CODE_CLERK_CLI_OAUTH_CLIENT_ID. CI has no such .env. Fixed separately in #45.

(An earlier revision of this description blamed vite's define: block. That was wrong — scoping define out of test mode left the tests failing unchanged.)

vp lint could not run in this environment at all, on this branch or on untouched files — oxlint fails to load oxlint-plugin-t3code/index.ts with ERR_UNKNOWN_FILE_EXTENSION under both Node 22 and Node 24. Lint coverage here is unproven locally; CI owns it.

Not verified in a real client. #6619 spans native headers, sheets, terminal, and code review, so a simulator pass is the obvious next step.

Model and harness: Claude Opus 5 via the review-t3-upstream skill in Pylon.

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