ci: point the iOS app at the test directory and restore the smoke test's search checks

With the test backend, the app is built against the test directory's address, and the smoke test goes on to search it: the Directory header above the results and their avatars in both layouts, the chat list's cards shown while typing and hidden under the results once the profile has a conversation, and "Show more" disabled while its page loads.

.github/workflows/ios-sim.yml

@@ -273,6 +273,14 @@ jobs:
         timeout-minutes: 30
         run: scripts/ci/ios-sim/backend.sh start ~/Downloads/${{ env.BACKEND_PKG }} "$RUNNER_TEMP/backend"
 
+      - name: Point the app at the test directory
+        if: env.START_BACKEND == 'true'
+        run: |
+          link=$(cat "$RUNNER_TEMP/backend/directory-link")
+          file=apps/ios/Shared/Model/DirectorySearch.swift
+          sed -i '' "s|^let DIRECTORY_SERVICE_LINK = \".*\"$|let DIRECTORY_SERVICE_LINK = \"$link\"|" "$file"
+          grep -F "let DIRECTORY_SERVICE_LINK = \"$link\"" "$file"
+
       - name: Build app
         run: |
           xcodebuild build -quiet \
@@ -294,6 +302,8 @@ jobs:
         run: scripts/ci/ios-sim/install-axe.sh
 
       - name: Run smoke test
+        env:
+          BACKEND_DIR: ${{ env.START_BACKEND == 'true' && format('{0}/backend', runner.temp) || '' }}
         run: scripts/ci/ios-sim/smoke-test.sh "$RUNNER_TEMP/DerivedData/Build/Products/Debug-iphonesimulator/SimpleX.app" "$RUNNER_TEMP/smoke-test"
 
       - name: Install Claude Code