IDML object styles: legacy all-corner attributes; parity notes the Object Style Options dialog

An object style that gives its corners only with `CornerOption` and
`CornerRadius` keeps them; at each level of the Based On chain a per-corner
attribute wins over those, as for page items. The parity assessment no
longer says there is no Object Style Options dialog.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

docs/target-app-parity.md

@@ -412,7 +412,7 @@ It is evidence of breadth: each item exists. It is not a claim of InDesign-level
 - Nested styles (through/up to N sentences, words, characters, letters, digits, tabs, breaks, spaces or given characters) and GREP styles (regex → character style), edited in Paragraph Style Options and composed under local formatting; `ui.dialog.open` for agents. Nested line styles are still to come; nested and GREP styles round-trip through IDML.
 - Table and cell styles (round-trip through IDML): cell styles (fill, insets, vertical justification, strokes, paragraph style) and table styles (region cell styles, border, alternating rows, spacing); apply from the Table panel, edits re-apply to every user; `style.cell.*`, `style.table.*`.
 - Style groups: paragraph and character styles shown in group folders, Move to Group (new, existing, none); `style.group` renames every use (styles, stories, table cells, footnotes, object styles).
-- Object styles carry effects: `style.object.create` keeps the selection's effects, `style.object.apply` sets them, and `style.object.edit {name, dropShadow?, feather?, …, effects?: null}` changes them on the style and on every item whose effects still match it (items with their own effects keep them; `style.object.clearOverrides` returns them to the style). New frames take their default style's effects. Effect values that aren't finite numbers are refused and the others clamped, in these commands and in the `object.*` effect commands. IDML carries only the drop shadow and feather, for ObjectStyles (read per effects category flag, settings from the BasedOn chain) as for items; the other effects stay in `.designcraft` files. There is no Object Style Options dialog yet.
+- Object styles carry effects: `style.object.create` keeps the selection's effects, `style.object.apply` sets them, and `style.object.edit {name, dropShadow?, feather?, …, effects?: null}` changes them on the style and on every item whose effects still match it (items with their own effects keep them; `style.object.clearOverrides` returns them to the style). New frames take their default style's effects. Effect values that aren't finite numbers are refused and the others clamped, in these commands and in the `object.*` effect commands. IDML carries only the drop shadow and feather, for ObjectStyles (read per effects category flag, settings from the BasedOn chain) as for items; the other effects stay in `.designcraft` files. Object Style Options is a dialog (from the Object Styles panel), with General, Fill, Stroke, Stroke & Corner Options, Paragraph Styles (with Apply Next Style) and Text Frame General Options pages.
 - Scrubby zoom: drag the Zoom tool left or right to zoom continuously around the press point.
 - Spring-loaded Zoom: hold Cmd+Space (Ctrl+Space on Windows/Linux) for the Zoom cursor and click/scrubby zoom; Alt-click zooms out. Release returns to the previous tool without changing the document or undo history. Text-frame and text-field typing suppress the shortcut; Space remains Hand.
 - Guides belong to the active layer: hidden with it (or with its Show Guides off) and locked with it.