Fill the window without scrollback, sandbox startup drill-down, --rebuild

[hbrooks]

What

Four connect-UI/CLI improvements from an interactive debugging session:

1. Bare agent owns the whole window, no more scrollback surprises

• runConnect soft-clears before the first Ink paint: newlines push the existing screen into scrollback, the cursor homes to row 1, so the app never starts mid-screen and overflows the window.
• The app reserves top padding (4 rows) above its first line. Two rows are visual breathing room; the rest is sacrificial slack that absorbs terminal row-accounting quirks and the one row the post-exit resume with: sign-off scrolls, so the sandbox startup notes always stay visible (during the run and after detach).
• The using config "X" (repo default) line for start --connect moved into the app's opening notice instead of printing before the render (which would land in scrollback). Other modes still print it.
• The post-exit resume with: agent session connect <id> line lost its leading newline and lands on a reserved row.

2. Sandbox startup: one line, rewritten in place, with drill-down

• The ✻ Starting sandbox… header shows a single current-phase line under it (Building image… · <latest output> → Ready!), replacing the stacked setup line + Sandbox ready · … transcript notice. Lifecycle records no longer render as transcript rows.
• ctrl+s opens the full step list (one step per setup hook, ✻ running / ✓ done, log line counts); ↑/↓ selects a step, → shows its logs (a live 5-line tail while the step runs, the stored log up to 100 lines once finished), ←/esc closes. Derivation is a pure deriveSandboxState with unit tests (accumulation across chunked records, reset on wake, --no-records cursor).

3. agent session start --rebuild

Sends force_rebuild: true so the initial provision skips the sandbox image cache (fresh full build whose snapshot refreshes the cache). Works from a bare agent --rebuild too, since bare invocations forward to session start --connect. Safe to ship ahead of the backend: unknown request fields are ignored, so the flag is a no-op until the server field lands (backend branch session-force-rebuild in the monorepo).

4. Version honesty

package.json bumped 1.0.0 → 1.1.0 to match the released v1.1.0 tag, which was cut without the bump commit. Dev builds (bun run compile) stop reporting v1.0.0; released binaries were unaffected (the workflow stamps the tag version at build time).

Testing

• tsc --noEmit clean; 210 vitest tests pass (9 new).
• Layout and interaction verified end-to-end by driving the real compiled binary in a scripted PTY (24x80 and 24x120) against a fake /v1 server that replays the sandbox lifecycle, then emulating the captured bytes with pyte: first paint never scrolls, the header survives exit, ctrl+s/arrows produce the step list, running tail, and finished log views.