fix(frontend): make inbound forms accessible to screen readers (#7025)

Expose selectable options and selected values, associate validation guidance with controls, and contain keyboard focus in inbound dialogs. Preserve create and edit serialization and add Chromium keyboard and accessibility checks.

.github/workflows/ci.yml

@@ -365,6 +365,15 @@ jobs:
       - name: Build Storybook
         run: npm run build-storybook
         working-directory: frontend
+      - name: Inbound keyboard and accessibility tree
+        working-directory: frontend
+        run: |
+          set -euo pipefail
+          ./node_modules/.bin/vite preview --outDir storybook-static --host 127.0.0.1 --port 6006 > /tmp/inbound-preview.log 2>&1 &
+          preview_pid=$!
+          trap 'kill "$preview_pid" 2>/dev/null || true' EXIT
+          curl --retry 30 --retry-connrefused --retry-delay 1 --retry-max-time 45 -fsS http://127.0.0.1:6006/iframe.html > /dev/null
+          node tools/check-inbound-keyboard.mjs http://127.0.0.1:6006
       - name: Audit
         run: npm run audit
         working-directory: frontend