[EmannuellaO]

Fixes #1173

Problem

Pressing ? on /draw-credit opened two overlays: App's document-level bubble listener (App.tsx) opened ShortcutHelpOverlay, then the draw wizard's window-level listener (DrawCreditPage.tsx) opened its own InlineHelpOverlay — two stacked modals, double-inerted backdrop, broken focus management.

Fix

• src/pages/DrawCreditPage.tsx — the wizard's shortcut handler now binds in the capture phase on document and always consumes ? (preventDefault() + stopPropagation()), so App's handler — which bails on event.defaultPrevented — never runs on this route. The wizard opens its contextual help only when no other modal is open; while an input is focused the key is ignored entirely (character insertion wins). Escape/arrows are gated behind any open [role="dialog"][aria-modal="true"] (scoped so the always-mounted, closed notification-center panel doesn't block shortcuts).
• docs/ACCESSIBILITY.md — new "Shortcut precedence" section documenting the page-level ? vs global ? contract.

Also included (needed for green acceptance + CI)

• Learn-mode regression fix: e3cb4ee dropped the ?learn=1 branch from handleRiskModalAcknowledge, so acknowledging in learn mode started writing the ack key; restored (verified against original 21ebc97 implementation). Same commit also introduced a TDZ error (handleRiskModalAcknowledgeAndFocus deps referencing a const declared below it) — fixed by reordering the callbacks (pre-existing in the worktree, load-bearing for any render of the page).
• Stale test expectations updated to current intended behavior: the risk gate is now a primer banner → modal flow (per e3cb4ee), and a failed draw's reset CTA is "Start over" (per #1179/a250566).
• Test-router stub (src/test/__mocks__/react-router-dom.tsx): real Routes/Route matching, BrowserRouter reads window.location, syncHistory() keeps jsdom's URL in sync — required for App-level routing tests. (Overlaps with the stub upgrade in fix: revalidate restored repay drafts and scope them to the wallet (#1188) #1323 — whichever merges second rebases.)
• useWalletIdentityKey mock in DrawCreditPage.test.tsx: 10 confirm-step tests were failing on main with "useWallet must be used within WalletProvider" (masked by a collection error until the @stellar/stellar-sdk dep below was added).
• @stellar/stellar-sdk dependency: without it no test file collects — npm run build/CI on main was red. Added to fix that pre-existing breakage.
• src/App.test.tsx: /help is a code-split route, so the input-focus test now awaits findByPlaceholderText instead of getBy… synchronously.

Test plan

New src/App.shortcuts.test.tsx (6 rows):

#	Assertion
1	/draw-credit + ? → exactly one dialog, and it is the wizard's Help Center (not "Move around faster")
2	? pressed again with help open → still exactly one dialog
3	/ + ? → global ShortcutHelpOverlay still opens (no behavior loss)
4	Risk primer modal open + ? → no second dialog stacked (WhyApr has no UI trigger in the current build, so the reachable DefaultRiskModal stands in for the "dialog already open" case)
5	? typed into the amount input → no overlay, still on the amount step, focus retained
6	Escape closes the wizard help → focus returns to the "Contact support" trigger

Verification

• npx vitest run src/pages/DrawCreditPage.test.tsx src/components/ShortcutHelpOverlay.test.tsx src/App.test.tsx src/App.shortcuts.test.tsx → 70 passed, 0 failed (5 pre-existing skips).
• Regression proof: with the pre-fix handler restored in isolation, 4/6 new tests fail — the old code stacks both overlays and double-inerts the app (aria-hidden on the entire tree).
• Full suite vs clean main baseline (both runs with the stellar-sdk dep): 374 → 317 failures, 0 new failures (58 fixed by this PR; the single diff — ConfirmDialog focus trap — passes in isolation 2×, a full-suite timing flake).
• npm run build → succeeds (CI's only job); tsc --noEmit → 334 errors, unchanged from baseline (repo-wide pre-existing debt; lint has no eslint config on main, pre-existing).