See the paren-face package. The diagram you mention sounds like the one in the repository README. (I think the diagram has been used in longer article too, but I’m not sure where it originated.)

Have a look at the approach taken by the logos.el package. There’s a section in the manual called Leverage logos-focus-mode-hook.

The idea there is that when you enable the logos-focus-mode, you’ll often want to change some other minor modes and variables too. But when you disable logos-focus-mode, you’ll want those other minor modes to revert to their previous value. The Logos package provides a few convenience functions to remember the previous values, and they are automatically restored when logos-focus-mode is turned off.

Perhaps the code for that could be made generic, instead of being coupled to the logos-focus-mode?

I keep a journal using org-roam-dailies. My headlines there include “Notes created” and “Notes updated”. I manually create links there as I go along; it’s no hardship to do that a dozen times a day, so I haven’t yet automated it.

The org-roam-timestamps package might be worth a look. It adds created/modified timestamp properties to org-roam nodes, and automatically updates these when saving the node.

An interesting feature is that it can optionally keep a sequence of modification timestamps, not just the last-modified timestamp.

It doesn’t actually change the SQLite schema though. All it does is update the properties in the Org file. (Org-roam considers the files to be canonical; the DB is really just a disposable index for speedy lookups.) The node table already has a properties column, so the created/modified timestamps end up buried in this.

The org-roam-timestamps package is a bit lacking in features, I’d say. All it does is save and update the timestamp properties for each Org-roam node. It doesn’t provide any useful query functions. I’ve had this package installed for ages, but I don’t really do anything with it. For now, it’s just collecting timestamps for the sake of posterity.

I have a vague idea to write some query functions, such as “what nodes did I create/modify on the same day as the current node?”. The results could populate a section in the Org-roam buffer (after the backlinks), or an Org dynamic block.

For a complete list, see the documentation of the marginalia--symbol-class function.

Aren’t those XDA profile keycaps?

I love how “ESC” and “CTRL” are quoted.

We’re expecting RET to perform minibuffer-exit. That’s the default keybinding from minibuffer-mode-map. Perhaps another keybinding (from another minor-mode keymap, say) is overriding the minibuffer’s RET binding.

it just goes to the next line

Hmmm, this sounds familiar. I had this problem last year.

Do you have Paredit mode enabled in the minibuffer? (You might look at the value of eval-expression-minibuffer-setup-hook.)

The paredit-mode-map has the paredit-RET command bound to RET instead. This command usually puts a new line in place.

For variables you created (i.e. named) yourself, you can also use defvar, which lets you give it a docstring.

To set a different value according to the OS, you can conditionally set the value based on a system-type.

    (defvar fuzzbomb/startup-theme 'modus-vivendi-tinted
        "The theme to enable during startup.

    This variable should be set before the first call to `load-theme' in
`init.el'.")

      (if (eq system-type 'windows-nt)
          (setq fuzzbomb/startup-theme 'ef-maris-light))