fix(dialog-editor): stop the selected-option inspector collapsing into one grey blob

In the focused-option view the option row (.trow.choicesel) painted a full-row
background of --vscode-list-inactiveSelectionBackground. In bgforge-monokai that
token equals --vscode-input-background (both #414339), so the row, every field's
own background, and the fields' borders were all the identical grey: the input
boxes had no visible edge and the panel read as bare text floating on one grey
blob, with no form structure. The node view was unaffected only because its rows
are not selection-washed, so the field backgrounds stand out against the darker
panel.

Drop the full-row fill; the focus-accent left border, the tree-row highlight, and
the "option #N" crumb already mark the selected option. Field backgrounds now sit
on the dark inspector panel (rgb 30,31,28 vs field rgb 65,67,57) and render as
distinct boxes again.

Author: burner1024

client/src/dialog-editor/webview/Inspector.svelte

@@ -780,11 +780,14 @@
         flex-direction: column;
         gap: 3px;
     }
-    /* The option selected from the tree: focus-accented left border + faint fill, matching the tree row's
-       selection, so the same option reads as selected in both panels. */
+    /* The option selected from the tree: a focus-accented left border marks it. Do NOT add a full-row
+       background fill here: list-inactiveSelectionBackground equals input-background in some themes
+       (bgforge-monokai: both #414339), so a fill paints the row the SAME colour as every field's own
+       background - the field boxes, their borders, and the row all collapse into one grey blob and the form
+       structure disappears (labels + values become bare text on grey). The left accent, the tree-row
+       highlight, and the "option #N" crumb carry the selection without touching field backgrounds. */
     .trow.choicesel {
         border-left-color: var(--vscode-focusBorder);
-        background: var(--vscode-list-inactiveSelectionBackground);
     }
     .trhead {
         display: flex;