Add accessibility wiring for modals

docs/design-system.md

@@ -75,6 +75,8 @@ For toggles:
 
 Compose them together when mounting new modal portals. If you need a drawer or sheet, start from these primitives and adjust spacing/positioning via utilities.
 
+Static modal partials (login, application, feedback, etc.) should call the helpers exported from `js/ui/components/staticModalAccessibility.js`—`prepareStaticModal`, `openStaticModal`, and `closeStaticModal`—to attach focus trapping, Escape/backdrop dismissal, and the shared `data-open`/`html.modal-open` toggles without duplicating controller logic.
+
 ### Popovers
 
 Use `.popover` as the relative anchor for floating content. Nest `.popover__panel` for the floating surface—it’s positioned absolutely below the trigger, inherits the shared focus ring, and animates with opacity/scale tokens. Toggle `[data-state="open"]` on the panel to switch between the collapsed (`opacity-0 scale-95`) and expanded (`opacity-100 scale-100`) states.

docs/qa.md

@@ -8,6 +8,7 @@ Before starting, open `docs/kitchen-sink.html` in a browser to review the modal
 * Scroll the modal content down and back up; confirm the sticky navigation bar hides on downward scroll and reappears when you reverse direction.
 * Activate the zap button to display the popover and tab through its fields to confirm focus stays within the dialog; press `Escape` to close it and ensure focus returns to the zap trigger.
 * Close the video modal first with `Escape` and again by clicking the dimmed backdrop; in both cases, focus should move back to the original trigger element you used to open the modal.
+* Repeat the accessibility spot check for the Upload, Edit, and Revert modals along with static dialogs (Login, Application form, Content appeals, Feedback, Feature request, Bug report, and Disclaimer). Ensure `Tab`/`Shift+Tab` stay within each modal and that pressing `Escape` or clicking a dismissible backdrop closes the dialog and restores focus to the opener.
 
 1. **Upload Modal Smoke Test**
    - Open the Upload modal, verify title is required, and ensure either a hosted URL or a magnet (or both) must be supplied.