fix(desktop): preserve setup on reopen and avoid false quit warnings

[davidmckayv]

What this changes

Reopening the macOS window reloaded setup and erased the current wizard step and API-key entry. Restore now preserves the current setup or owned application page, including its route, while retaining deployment ownership and recovery checks.

Quitting after only viewing setup also reported a container cleanup failure when an old Compose file existed. Quit now cleans containers owned by the session; failed starts retain ownership and still report real shutdown failures. Explicit Stop continues to reject unknown runtime ownership.

Where it runs

Desktop shell only.

• New state that outlives a request: none; existing WebView and session ownership are retained.
• Second replica: server behavior is unchanged.
• Serialization: existing startup lock covers restore and shutdown ownership.
• Browser fan-out: none.
• New listener, port, or schedule: none.

Boundary and audit

• Acting calls and gateway boundaries are unchanged.
• No new server refusals or failures; genuine native shutdown failures retain their existing notice path.
• No new client trust.

Changelog

The deployed server behaves identically; these fixes affect only local desktop window restoration and setup-only Quit.

Proof

• Reproduced the wizard reset in the installed macOS app; verified the patched native bundle retains input after switching away/reopening and closing/reopening its window.
• Reproduced the false shutdown notice, then verified clean Quit and relaunch without another warning. Installed and checked local build 0.0.10-internal.g123057ad91bb.
• Rust library: 440 passed, 3 pre-existing ignored. Final desktop binary: 134 passed.
• Rustfmt, Clippy, native Tauri bundle build, and signature verification passed.
• Existing cross-platform CI retained. Newer main changes only the desktop package version, with no changes to the affected Rust code or dependencies.

Report: https://copilotkit.slack.com/archives/D0C2VM6KEBA/p1789490973618219