Utterform 0.7.11 — Windows autostart registration

This patch repairs Settings → General → Start Utterform when I sign in on Windows. The per-user Run entry now quotes the installed executable path, includes --autostart, and is read back together with Windows' StartupApproved state. An absent, disabled, malformed or stale registration is not shown as enabled. Explicitly enabling startup clears a previously disabled Windows override.

The NSIS installer retains an existing enabled choice during an in-place upgrade and repairs its executable path. Uninstall removes both startup values. Linux and macOS continue to use the existing Tauri autostart plugin.

Verification and follow-up

Automated tests cover command quoting, exact read-back, disabled/malformed approval values and registry create/remove on Windows. A Windows build alone does not establish sign-in behavior. On September 30, the release was explicitly authorized before the manual desktop test because that test will be performed separately. Issue #40 stays open until that evidence exists.

On an installed Windows 11 build, enable startup, inspect the registry, sign out and in, and verify one hidden tray process without focus or recording. Then disable it and repeat sign-in; test an in-place upgrade and uninstall cleanup. Record the result without publishing user-specific paths.