+1 for plain-text for all the points you mention, particularly "data-first with tools on top". But why reinvent the wheel when the org-mode format is well established and does everything you want, and more?
There are an increasing number of tools using org-mode as a plain-text data store, so you are more likely to be able to participate in a tool ecosystem. In addition to my own https://braintool.org see the list below. BrainTool (mainly a bookmark manager) has an elemental to-do system, I'd love to have my users be able to use your tool for todos.
There are an increasing number of tools using org-mode as a plain-text data store, so you are more likely to be able to participate in a tool ecosystem. In addition to my own https://braintool.org see the list below. BrainTool (mainly a bookmark manager) has an elemental to-do system, I'd love to have my users be able to use your tool for todos.
NB see also Karl Voit's push for org markup awareness outside of Emacs via Orgdown: https://gitlab.com/publicvoit/orgdown.
------ ORG-MODE TOOLS OUTSIDE EMACS
https://plainorg.com
https://flathabits.com
https://beorg.app
https://braintool.org
https://easyorgmode.com
https://logseq.com
https://organice.200ok.ch
https://orgro.org
http://orgzly.com