feat(ui): add win_opts for dev log and outline windows

[sidlatau]

• Add dev_log.win_opts and outline.win_opts: window-local options applied when the window opens, e.g. { winfixheight = true } keeps the dev log height when wincmd = runs on resize.
• Options are applied after the outline's own window setup, so they can override its defaults.
• An invalid option name warns instead of failing to open the window.

Closes #474