feat(emacs): add function to quickly open a parent/child

feat(emacs): add search related hotkeys to list buffer

feat(emacs): add function to customize item content buffer window

fix(emacs): list refresh resets the search string

feat(emacs): make content window split customizable

feat(emacs): add more hotkeys to list mode

feat(core): delete extra logging

refactor(core): enhance search parser & engine implementation

fix(core): match operator is not recognized as special operator

feat(core): implement has search query

fix(emacs): broken delete link

feat(emacs): implement item property functions

feat(emacs): adjust to item core APIs

feat(core): implement reference api

feat(core): implement logging level adjustment

feat(core): split http server and main function

feat(core): split http server and main function

feat(scala): redesign search engine

feat(emacs): implement major mode dispatcher

feat(emacs): add attachment hotkeys

feat(emacs): handle item content buffer more gracefully

feat(emacs): re-design item buffer management

feat(emacs): change the buffer name prefix

feat(emacs): redesign item and content functions

feat(core): enhance search syntax

fix(emacs): adopt new API

fix(emacs): update client to get item

refactor(core): enhance API quality

feat(core): implement reference CRUD

fix(core): invalid test failure