Remove the hardcoded statusline_offset from calculate_position() and
let padding.y serve as the sole offset from the bottom edge. Bump
default padding.y to 3 to preserve the original visual position.
Add indicator.padding (x, y) to offset the status indicator from the
editor edges. Defaults to 1 cell on each axis, moving the indicator
away from the right edge and bottom of the buffer.
Introduce config module for managing user options, defaults, and watchexec
binary discovery. Add window module for creating and managing the output
window (float or split) with append, clear, resize, and keymap support.