docs(README): credit the video-game radial lineage; foreground one-handed typing

- Name video games as the source for the radial/pie menu (weapon/emote wheel)
  alongside acme/sam/plumber, Emacs, and Sublime.
- Stop understating the one-handed-typing shift: state plainly that it is the
  driving ergonomic constraint — the reason the mouse carries the reaching and
  chords are off the table — in the intro, the design-constraints list, and the
  radial section.

README.md

@@ -5,7 +5,15 @@ live in Plan 9's [acme](http://acme.cat-v.org/) most of the time, but I like a
 lot of what Kate offers — and I don't like menu-driven workflows. So this is a
 suite of Kate / KTextEditor plugins that pulls in ideas from the tools I reach
 for — acme, sam, and the plumber from Plan 9; `M-x` from Emacs; a Sublime-style
-fuzzy palette — and bends Kate toward them.
+fuzzy palette; and the radial/pie menus that video games have used for years to
+put actions a flick away from the cursor — and bends Kate toward them.
+
+The deeper reason is ergonomic: I've moved to typing one-handed, and that
+reshapes everything. A workflow built on two-handed chords and reaching across
+the keyboard simply doesn't work anymore. The mouse does the reaching, the
+keyboard stays under one hand, and no action is allowed to require a chord or an
+F-key. This isn't a preference knob — it's the constraint the whole design is
+built around.
 
 The aim is a text editor driven by the mouse at the cursor and by plain-letter
 keyboard input — never by hunting through nested menubars or memorizing complex
@@ -16,8 +24,11 @@ chords.
 These are hard constraints that shape every decision:
 
 - **Mouse-heavy.** The fastest input is the mouse, used *locally* at the caret
-  (radial / floating surfaces), not a trek to the menubar.
-- **One-handed typing.** Keyboard input must work comfortably with one hand.
+  (radial / floating surfaces, in the spirit of a game's weapon wheel), not a
+  trek to the menubar.
+- **One-handed typing (the driving constraint).** Input must work comfortably
+  with a single hand. This is not a convenience toggle; it is why the mouse
+  carries the reaching and why chords are off the table.
 - **No complex chords.** Single modifier at most (`Ctrl`+letter). No leader-key
   chord trees, no multi-cursor keybinds.
 - **Compact keyboard.** F-keys and nav clusters live on a layer toggle, so they
@@ -199,7 +210,9 @@ discovered from the active document (VCS root, else its directory).
 ![The Deft radial caret menu](docs/img/deft-radial.png)
 
 A multi-level pie menu for actions that **complete in place** (cut, copy, paste,
-comment, case changes…), so the mouse stays at the text.
+comment, case changes…), so the mouse stays at the text. The model is the
+weapon/emote wheel from games: a quick flick toward a direction, not a hunt
+through a list.
 
 - **Open:** `Alt+R` (at the caret) **or press the right mouse button** in the
   editor (at the pointer; the normal context menu is suppressed while enabled).