feat(launch): tabs from the first frame, a skeleton while the agent comes back (#106)

[Maxaubert]

Closes #106. Spec and plan, approved together ("go ahead"): docs/superpowers/specs/2026-09-30-launch-skeleton-design.md. The four mockups sit next to it (2026-09-30-launch-mockups.html); the owner picked C, the skeleton.

Before: opening the app with three Claude tabs showed the start screen ("no tabs"), then the tabs, then text on each tab, then Claude.

After:

• Tabs from the first frame.
  • tabs:peek is a synchronous read of tabs.json: no stat, no session scan. It draws the saved strip as placeholders (Tab.pending) at once.
  • When tabs:restore answers, lib/restorePlan settles each placeholder in place by its saved index (RestoredTab.from).
  • A placeholder whose folder is gone, or that was closed meanwhile, goes away. Folders handed to the launch come after.
  • The start screen shows only after a restore that answered empty.
• A skeleton while the agent comes back (core, so Prism's resumed terminals get it too).
  • ResumeSkeleton draws Claude's layout as quiet theme-coloured bars: the logo block, a prompt, a reply, the input box, the footer.
  • resumeReveal, pure and tested, decides when. MEASURED 2026-09-30: under pwsh through the bundled ConPTY, the first title is exactly claude (3.6 s), then ✳ Claude Code (5.4 s), then the alternate screen.
  • A local clear (screen and scrollback) is written just BEFORE the claude title, so nothing the shell said is seen.
  • The skeleton fades out on the agent's next title or the alternate screen, plus 150 ms. It also lifts on a key, an exit, a failed spawn, or at 12 s.
  • A folder path is never taken for the program: the owner's projects live under a folder called Claude.
  • The old text spinner is gone.
• A ring on every tab still coming back, in the strip. resumingIds in termBus; placeholders count too.

Core 0.20.0, app 0.25.0. Prism gets the skeleton through the automatic bump. Its tab strip can adopt the ring later.

Verified:

• Unit tests: 994 pass, including resumeReveal and restorePlan (peek, settle, a closed placeholder, the handed-over folders, all gone). Lint and typecheck pass.
• New e2e launchSkeleton runs three saved claude tabs, a temp HOME with a transcript for each (never the real ~/.claude), and a stand-in claude first on PATH. The stand-in prints a line first, titles itself claude, prints its banner, then settles like the real one.
  • It asserts:
    • the first frame holds three tabs and no start screen;
    • the skeleton and three rings show during load;
    • what came before the agent is never shown uncovered, and is gone afterwards;
    • the agent appears and the skeleton and rings go;
    • a background tab opened later shows its agent at once.
  • On main, 5 of its 7 checks fail. The other 2 were already true there.
  • .e2e-shots/launch-skeleton.png was checked against the mockup.
• Full e2e suite passes. edges failed on its relaunch step in one full run and once on its own, then passed three times in a row, including a clean full run; it failed the same way once before this change. attention failed once in the first full run and passed on its own.

🤖 Generated with Claude Code

https://claude.ai/code/session_01FHHaWKR4M5QtW7Wecyuk4t