Adds a dot next to entries whose path matches an open buffer (with directory rollup, so an ancestor of any open file gets the dot too) and a render mode that auto-hides the panel when the terminal is narrow *and* the panel isn't focused — pressing `<space>e` brings it back as an overlay until focus drops again. The colon-passthrough comment in the keymap is also updated to note that dropping focus is what triggers the auto-hide.