fix(widget): correct visibility icon polarity in section menu (JS-9858)

[requilence]

The widget section menu (src/ts/component/menu/widget/section.tsx) was the wrong one: it rendered item.isHidden ? 'common/eye1' : 'common/eye0', i.e. a slashed eye on hidden rows and an open eye on visible ones, the exact opposite of the Manage Sections sidebar panel. Everywhere else in the app the eye icon depicts the action the click performs, not the current state — common/eye0 is the plain open eye ("show"), common/eye1 the slashed eye ("hide"). That is pinned by the two call sites where the icon sits next to an explicit label: menu/dataview/group/edit.tsx pairs Show column with eye0 and Hide column with eye1, and menu/dataview/relation/edit.tsx pairs Hide Property with eye1. sidebar/page/widgetManage.tsx follows the same rule and its tooltip proves it (isHidden → eye0 + "Show section"), as does the passphrase reveal toggle in form/phrase.tsx. The menu was the only outlier; it also already conveys state independently through the .isHidden dimming class (src/scss/menu/widget.scss), so the icon is free to carry the action. One-token fix, no styling touched.

Closes #2244 · JS-9858

The reporter's literal complaint — hidden sections continuing to render in the sidebar — is a false alarm: sidebar/page/widget.tsx gates on if (ws.isHidden) return null; and S.Common.widgetSectionsSet persists immediately (no "Done" needed). What they hit was the inverted icon, which made them read "slashed eye" as "already hidden". Worth saying so in the reply to them.

How to test

1. Open the left sidebar and its section context menu (... on a section) → Manage sections, and note the eye icon on a visible row: it is the slashed eye, tooltip "Hide section".
2. Click it. The section disappears from the sidebar, the icon becomes the open eye and the tooltip becomes "Show section".
3. Click it again to restore the section — the icon returns to the slashed eye.
4. Open the widget section menu (the older widgetSection menu with the same list) and check the same rows: visible rows now show the slashed eye and hidden rows the open eye, matching the sidebar panel. Hidden rows also stay dimmed.