chore: sync upstream main

[tarik02]

What Changed

• Merged 111 upstream commits through pingdotgg/t3code@949feb61e.
• Preserved the fork release workflow, README, goal projection, and provider launch environment handling.
• Kept the fork's existing mobile screenshot workflow instead of importing the upstream multi-theme matrix.
• Left out upstream AUR packaging and install instructions because the fork does not publish those packages.
• Updated the fork goal UI for upstream's new tooltip lint rule.

Why

Brings the fork to current upstream after #134 without adding release paths the fork cannot support.

UI Changes

This imports upstream web, desktop, and mobile UI changes. Screenshots were not captured because browser verification was not requested.

Verification

• lowio corepack pnpm install --frozen-lockfile
• lowio corepack pnpm exec vp run --filter t3 --filter @t3tools/desktop --filter @t3tools/web --concurrency-limit 2 typecheck
• lowio corepack pnpm exec vp run --filter @t3tools/web typecheck after the goal tooltip fix
• lowio corepack pnpm exec vp lint --report-unused-disable-directives on the resolved and amended TypeScript files
• The first CI run passed every test shard; its only failure was the two goal tooltip lint errors fixed in the amended commit
• Confirmed the merge parents are current org/main and exact upstream/main

Checklist

• This PR is focused on one upstream sync
• I explained what changed and why
• I included before/after screenshots for UI changes
• I included a video for animation or interaction changes

Made with gpt-5.6-sol using the Codex harness in T3 Code.

[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	10.5 KiB	11.8 KiB	+1.3 KiB (+12.2%)	15.1 KiB	✅
Codex	Thread snapshot wire	4.8 KiB	5.6 KiB	+828 B (+16.9%)	7.3 KiB	✅
Codex	Live turn WebSocket wire	5.7 KiB	6.2 KiB	+487 B (+8.3%)	7.8 KiB	✅
Codex	Live turn WebSocket decoded	50.3 KiB	52.4 KiB	+2.1 KiB (+4.2%)	66.4 KiB	✅
Codex	Live turn messages	10	10	0 (0.0%)	21	✅
Claude	Total thread wire	10.5 KiB	11.8 KiB	+1.3 KiB (+12.1%)	15.1 KiB	✅
Claude	Thread snapshot wire	4.8 KiB	5.6 KiB	+820 B (+16.7%)	7.3 KiB	✅
Claude	Live turn WebSocket wire	5.7 KiB	6.2 KiB	+479 B (+8.2%)	7.8 KiB	✅
Claude	Live turn WebSocket decoded	51.1 KiB	53.2 KiB	+2.1 KiB (+4.1%)	66.4 KiB	✅
Claude	Live turn messages	10	10	0 (0.0%)	21	✅

Baseline: d81ed9a · PR result: fd74377 · 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: 81.5 KiB
• Claude decoded thread snapshot: 81.9 KiB

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