fix(web): continue onboarding after incomplete history imports

[t3-code]

problem

A single failed history import leaves onboarding on the Projects step even when other threads imported successfully, as reported in https://x.com/emkara/status/2103985692032553420.

change

Finish setup after the import attempt, keep the existing landing-project selection, and show a persistent, dismissible warning after workspace navigation completes. Successful imports show an "Imported N threads" success toast after navigation; empty or skipped imports do not show success. Failure to save onboarding completion still keeps setup open, and retrying completion preserves the import warning.

Applies to the shared web/desktop onboarding wizard, including remote environments. No server, import protocol, provider adapter, or mobile changes.

verification

• Regression reproduced before the fix: the actual wizard never completed with 28 imported threads and 1 skipped thread.
• 29 focused tests pass, covering navigation ordering, partial/all-skipped/full/empty imports, completion-save retry, and existing project-selection behavior.
• Web typecheck and formatting pass. Targeted lint reports existing warnings in the wizard; no errors.
• Real Chromium app run against an isolated T3 home with 29 synthetic Claude transcripts: the real server imported 28 and rejected one invalid session ID. Before: remained in setup. After: navigated to a project draft and displayed the warning. No mocked import responses or real provider conversations.
• Independent pre-commit reviewer unavailable locally; repository review pending.

before

after

successful import

transition recording

Real browser frames, captured with the synthetic transcript fixture described above.

https://t3bot-uploads-production.up.railway.app/files/tntwcyH19sZhUhihqx1f7m8J/onboarding-import-transition.mp4

request provenance

Requested by @extoci. Success notification requested by @UtkarshUsername.

Model: gpt-6-astra. Harness: Hermes Agent.

[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	13.5 KiB	13.5 KiB	−19 B (−0.1%)	15.1 KiB	✅
Codex	Thread snapshot wire	7.1 KiB	7.1 KiB	+5 B (+0.1%)	7.3 KiB	✅
Codex	Live turn WebSocket wire	6.5 KiB	6.4 KiB	−24 B (−0.4%)	7.8 KiB	✅
Codex	Live turn WebSocket decoded	56.3 KiB	56.2 KiB	−44 B (−0.1%)	66.4 KiB	✅
Codex	Live turn messages	10	9	−1 (−10.0%)	21	✅
Claude	Total thread wire	13.5 KiB	13.5 KiB	+11 B (+0.1%)	15.1 KiB	✅
Claude	Thread snapshot wire	7.1 KiB	7.1 KiB	+3 B (+0.0%)	7.3 KiB	✅
Claude	Live turn WebSocket wire	6.4 KiB	6.4 KiB	+8 B (+0.1%)	7.8 KiB	✅
Claude	Live turn WebSocket decoded	57.0 KiB	57.0 KiB	0 B (0.0%)	66.4 KiB	✅
Claude	Live turn messages	9	9	0 (0.0%)	21	✅

Baseline: a727d1d · PR result: 63e764f · 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: 114.0 KiB
• Claude decoded thread snapshot: 114.7 KiB

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

[macroscopeapp]

Approvability

Verdict: Approved at 63e764f

Macroscope's review found this PR approvable — This is a focused onboarding bug fix that lets users continue after incomplete history imports while preserving the selected project and reporting partial results after navigation. It changes only two production files and adds targeted regression coverage, with no schema, server, security, deployment, default, or linting-impacting changes.

^{You can add or adjust custom eligibility rules. Learn more.}

Dismissing prior approval to re-evaluate 63e764f