merge: fold the #569 review fixes into the alias-aware layout rows

Four commits landed on this branch from review while the layout wiring was in
progress, and the two solved overlapping problems differently.

Theirs made elementKeys() append every layout-only key, matched by exact name.
Against football that also lists `score` and `odds` -- entries the alias
resolution already pairs with score_text and odds_text -- so those offsets
would get two controls posting the same field. The row split here
(styleRows via core's x-layout-key, positionRows for what nothing claims)
replaces that append; elementKeys() is back to listing style elements only.

Theirs also covered cases this side had missed, all kept:
- A leaf straight under layout (a show_logo toggle, no x/y object) now gets a
  position row with a self-keyed column bound to customization.layout.<key>.
  Core no longer lets an element claim a leaf as its offsets.
- Leaf columns keep their namespaced id, so a leaf sharing a name with another
  entry's axis cannot be shadowed.
- columnsFor(schema) still works with one argument (every row), so their
  column tests run unchanged.
- The owned key is CSS.escape()'d before it becomes a selector.

test_style_editor_element_keys.js is rewritten for the new contract, and says
why the old one had to go. All six JS suites pass; in a browser football's 92
layout fields each render once, and a synthetic leaf -- including one named
`scale` alongside a `scale` axis -- gets exactly one correctly named control.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

web_interface/templates/v3/partials/plugin_config.html

@@ -159,8 +159,13 @@
                         var owned = (container.dataset.ownedKeys || '')
                             .split(',').filter(function (k) { return k; });
                         owned.forEach(function (k) {
+                            // CSS.escape: k is a schema property key read
+                            // back off dataset.ownedKeys, not a literal --
+                            // building the attribute selector by raw
+                            // concatenation would break (or be steerable)
+                            // on a key containing a quote or backslash.
                             var node = fallback.querySelector(
-                                '[data-child-key="' + k + '"]');
+                                '[data-child-key="' + CSS.escape(k) + '"]');
                             if (node) { node.remove(); }
                         });
                         // Nothing left but the section heading, or a widget