[contursofran]

Part of #713 (slice S2): the first launch opens Settings → Setup (D280).

Steps

1. Settings.FirstSetup runs the setup checks once at start, off the UI thread, and gives the frame the number of required steps left (hc core not counted, it can still be connecting). Settings.OpenSetup opens the modal on the Setup tab without a new pass. No timer.
2. prefs.SetupSeen (setupSeen, missing = false), loaded in StartTheme and written by persist.
3. Frame.firstSetup: steps > 0 and not seen → open on Setup once, store setupSeen.
4. Deps.SetupRun / Settings.SetupRun: test seam for the pass; nil runs setup.Run.
5. e2e harness: settings.json gets setupSeen: true unless h.firstLaunch, so other e2e tests and see fixtures do not get the Settings modal on top.
6. Docs: docs/spec/SettingsSetup.md, D280.

Tests

• TestSetupSeenSaveThenLoad, TestFirstLaunchOpensSetupOnceAndStoresIt, TestSetupDoesNotOpenWhenSeen, TestSetupDoesNotOpenWhenAllReady, TestFirstSetupCountsStepsWithoutTheCoreAndOpensOnSetup, TestFirstSetupWithoutEnvDoesNothing.
• e2e go test -tags e2e -run TestSetupFirstLaunch ./cmd/contr: PASS (first launch opens Setup, second launch shows only the dot).

Pre-check

1. Tests: seen failing with the change undone: the three frame tests (no FirstSetup call; no seen guard; no steps > 0 guard) and TestSetupSeenSaveThenLoad (field not stored).
2. Plan: S2 steps done; the hc core is left out of the first-launch count (see D280).
3. Contract: setupSeen JSON field, D280.
4. Up to date with main; no open PR touches internal/app/attach.go.
5. Diff read: no leftovers.
6. Coverage: S2 only; S3 left to its slice.
7. Duties: nothing removed.
8. Evidence: tmp/e2e/setup-first-launch.png (local).