docs/ux: draw the offer as a vertical list too, and it wins

Tommaso was not sure about the ring and proposed a vertical list: left-click
selects, right-click exposes icon / name / shortcut. Drawn, it is better, and
the reasons are visible in the renders rather than arguable.

THE DISABLED ROW CAN SPEAK. This is the one that decides it. A ring slot that
does not apply is an empty circle: it says nothing, and on a fresh document six
of the eight are empty. A list row that does not apply is greyed IN PLACE with
its own name and its own reason — "Create a sketch, or pick a solid face,
first", "Create a solid body to pattern first" — which are strings the product
already ships and which tool_atlas.json already carries. The first-run picture
stops being a mostly-empty ring and becomes a map of what the product does and
what you must do first. For the audience section 2 puts first, that is the
whole ballgame.

THE OVERFLOW DISAPPEARS. Sketch Create needs nine addresses; a ring of eight
pushed Polygon and Point behind a "More" slot. Nine rows is just nine rows. The
one measured defect in the ring design is not a defect in this one.

SHORTCUTS READ AS A COLUMN. Right-aligned in a list they stack into something
the eye learns passively, which is exactly the graduation path 4.1 claims —
and it is the mechanism by which the power user Tommaso describes stops opening
the menu at all. Around a ring the same keys are eight loose chips.

Also, unglamorously: long translated names fit, arrow keys and screen readers
work natively where a radial needs special handling, and a 324px box costs the
1366x768 machine far less than a 380px disc over the model.

What the ring keeps: equidistant targets and a future flick gesture. Since the
brief is that power users live on the keyboard, that buys less than it looks.

The invariant is untouched — same eight families, same fixed order, nothing
re-sorted, nothing compacted. Only the geometry changed, which is the point:
the map survived a change of form factor, so it was a real map.

Both forms are now rendered side by side for the same states, and the atlas
opens with the pairs.

snaporca-96r.

docs/ux/offer_atlas.html

@@ -36,6 +36,16 @@
  </div>
 </header>
 <main>
+ <h2>Decision 0 — ring or vertical list</h2>
+ <p>The live question. Both forms carry the SAME map and the same invariant — fixed order, never
+ re-sorted, nothing compacted; only the geometry differs. Left-click selects; right-click opens the
+ offer. What the list buys: a disabled row can state its own reason in the words the product
+ already ships, where an empty slot in a ring is mute; nine sketch primitives fit without an
+ overflow; shortcuts line up in a readable column; long translated names fit; and it is navigable
+ by arrow key and by screen reader, which a radial is not. What it costs: no equidistant flick
+ gesture, and travel to the last row is longer than to the nearest direction. Pairs below —
+ list first, the same state as a ring second.</p>
+
  <h2>Decision 1 — ring capacity</h2>
  <p>The same three selections at eight and at twelve. Eight keeps 45° between neighbours, which is
  the reliable eyes-free pointing threshold and maps 1:1 to the numpad; twelve buys direct addresses