feature: allow focusing the Sidekick CLI window without calling `startinsert()`

[tummetott]

Did you check the docs?

• I have read all the sidekick.nvim docs

Is your feature request related to a problem? Please describe.

When reopening an existing Sidekick CLI session, I often want to jump back to the Sidekick window and keep the current scroll/view position.

Today, focus = true does two things at once:

• it focuses the Sidekick window
• it calls startinsert()

For long-running CLI sessions with lots of history, this is problematic. If I scroll up in the Sidekick terminal, hide the window to save screen space, and later reopen it, the normal focus path puts me back into terminal mode and jumps to the live prompt at the bottom.

In practice, I want to separate:

• focusing/selecting the Sidekick window
• entering terminal mode with startinsert()

Those are currently bundled together.

Describe the solution you'd like

I would like a way to focus the Sidekick CLI window without automatically calling startinsert().

A possible API could be an additional option such as startinsert, for example:

require("sidekick.cli").toggle({
  focus = true,
  startinsert = false,
})

Expected behavior:

• focus = true, startinsert = true
  Current behavior: focus the window and enter terminal mode.
• focus = true, startinsert = false
  Focus the window, but keep normal mode and preserve the current scrolled view.
• focus = false
  Show/hide without moving the cursor to the Sidekick window.

Describe alternatives you've considered

I currently work around this by mapping <c-.> to this function:

function()
    local Cli = require('sidekick.cli')
    local State = require('sidekick.cli.state')

    if not next(State.get({ attached = true, terminal = true })) then
        Cli.focus({ filter = { installed = true } })
        return
    end

    State.with(function(state)
        local t = state.terminal
        if not t then
            return
        end
        if t:is_open() then
            t:hide()
            return
        end
        t:show()
        vim.api.nvim_set_current_win(t.win)
    end, {
        filter = { attached = true, terminal = true },
        focus = false,
    })
end

That works, but it relies on require("sidekick.cli.state"), which appears to be internal API.

Additional context

No response