fix(app): reopen window from menu bar

[mahype]

Why

After closing the main window, the menu bar Open action could keep using an openWindow closure captured from that closed window. With the Dock icon off, the app is also in accessory mode when reopening.

What

• Use the menu bar scene live openWindow action for Open and pending approvals.
• Restore regular activation before reopening, then activate the app.

Verification

• Swift app build (full Xcode): passed.
• TorroMailKitContract: passed.
• cargo test --workspace --locked and cargo build -p torromail-mcp --locked: passed.
• Interactive menu bar click still needs confirmation on the installed app before tagging the next release.