ResponsiveModal → Dialog + accessibility improvements

[jpye-finch]

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Summary

• Migrate ResponsiveModal → Dialog (28 call sites) across packages/client and packages/login. Replaces the legacy show/handleClose/responsive/autoHeight/contentHeight API with isOpen/onClose; adds variant="large" where a width prop was present. Net deletion: 44 lines.
• Accessibility hardening (Dialog.tsx + useDialogA11y.ts):
  • Body scroll lock via a module-level openDialogCount counter — nested dialogs don't prematurely restore scroll when an inner dialog closes.
  • Focus-on-open via requestAnimationFrame; return-focus-on-close to the triggering element.
  • Escape key closes the dialog; Tab/Shift+Tab cycle is trapped within the dialog's focusable children.
  • aria-modal="true", aria-labelledby (stable useId-generated), aria-describedby wired to DialogContent.
  • Close button now conditionally rendered — omitted entirely when no onClose is provided (e.g. ReloadModal), preventing an inert keyboard target.
  • onClose removed from useEffect deps; a useRef wrapper keeps the callback current without triggering spurious effect cycles on inline-function re-renders.
• Responsive fixes (Dialog.tsx):
  • Large-variant mobile breakpoint: @media (max-width: 768px) and
    (orientation: portrait) → @media (max-width: ${theme.grid.breakpoints.lg}px) — portrait qualifier removed so
    landscape phones get the full-screen treatment.
  • Footer actions stack column-reverse at [breakpoints.md](http://breakpoints.md/) and below, each button full-width — primary action stays visually first on mobile.

[github-actions]

Oops! Looks like you forgot to update the changelog. When updating CHANGELOG.md, please consider the following:

• Changelog is read by country implementors who might not always be familiar with all technical details of OpenCRVS. Keep language high-level, user friendly and avoid technical references to internals.
• Answer "What's new?", "Why was the change made?" and "Why should I care?" for each change.
• If it's a breaking change, include a migration guide answering "What do I need to do to upgrade?".

[github-actions]

ℹ️ Coverage metrics explained:
• Statements — Executed code statements (basic logic lines)
• Branches — Tested decision paths (if/else, switch, ternaries)
• Functions — Functions invoked during tests
• Lines — Source lines executed

[github-actions]

📊 commons test coverage

Statements: 75.48%
Branches:   39.88%
Functions:  56.85%
Lines:      75.05%
Updated at: Fri, 08 May 2026 15:11:28 GMT

[github-actions]

📊 events test coverage

Statements: 86.86%
Branches:   84.93%
Functions:  92.08%
Lines:      86.86%
Updated at: Fri, 08 May 2026 15:20:11 GMT