test(expo): verify theme delivery in a unit test; drop fragile pixel-check

The Maestro screenshot pixel-check for theming was unreliable: it asserted a
hardcoded color against a screenshot whose primary-colored button is disabled
(empty email field on a clean launch) and rendered at a degraded 320x640 CI
emulator resolution — so it consistently 'failed' even though the theme applied.

Per the layer split, @clerk/expo owns theme DELIVERY (the config plugin embeds
the theme into iOS Info.plist + Android assets); the color RENDER is the native
SDKs' responsibility. So:

- Add a deterministic config-plugin unit test (appPlugin.theme.test.js) that
  runs withClerkTheme and asserts it embeds the parsed theme into the Info.plist
  mod and queues the Android assets mod — and is a no-op without a theme prop
  (the original 'bare @clerk/expo plugin string' regression). Runs in turbo
  test on every PR; no emulator, no screenshot.
- Remove the theming Maestro flows, verify-themes.sh, check-theme-color.js,
  pngjs, the CI 'Verify theming' steps, and the runner post-steps.

Author: chriscanin

.github/workflows/mobile-e2e.yml

@@ -597,15 +597,6 @@ jobs:
             | while read f; do grep -qE "^[[:space:]]*-[[:space:]]*(${pattern})[[:space:]]*$" "$f" || printf '%s\n' "$f"; done
             | xargs -n 1 -I FLOW bash -c 'flow="$1"; for a in 1 2; do if maestro test --env CLERK_TEST_EMAIL="$CLERK_TEST_EMAIL" --env CLERK_TEST_PASSWORD="$CLERK_TEST_PASSWORD" --flatten-debug-output "$flow"; then exit 0; fi; if [ "$a" -eq 2 ]; then echo "::error::Flow $flow failed after 2 attempts"; exit 1; fi; echo "::warning::Flow $flow failed attempt $a, retrying after 10s..."; adb shell am force-stop com.clerk.clerkexpoquickstart >/dev/null 2>&1 || true; sleep 10; done' _ FLOW
 
-      # Theme verification is a Node post-step (Maestro can't decode PNGs in its
-      # JS sandbox). The theming flows wrote theme-light.png / theme-dark.png to
-      # integration/mobile; this asserts each contains a large region of the
-      # expected themed color. Runs on success OR failure so a flaked flow
-      # doesn't hide a theming regression; skips cleanly if no theme shots exist.
-      - name: Verify Android theming
-        if: success() || failure()
-        run: bash integration/mobile/scripts/verify-themes.sh
-
       - name: Upload Maestro artifacts on failure or cancel
         if: failure() || cancelled()
         uses: actions/upload-artifact@v4
@@ -1039,13 +1030,6 @@ jobs:
               done
             ' _ FLOW
 
-      # Theme verification is a Node post-step (Maestro can't decode PNGs in its
-      # JS sandbox). iOS runs the light theme only (dark-mode is androidOnly);
-      # verify-themes.sh skips any theme shot that wasn't produced.
-      - name: Verify iOS theming
-        if: success() || failure()
-        run: bash integration/mobile/scripts/verify-themes.sh
-
       - name: Upload Maestro artifacts on failure or cancel
         if: failure() || cancelled()
         uses: actions/upload-artifact@v4

integration/mobile/flows/theming/custom-theme-applied.yaml

@@ -38,24 +38,10 @@ if [[ ${#KEEP[@]} -eq 0 ]]; then
   exit 0
 fi
 
-# Run maestro from integration/mobile so `takeScreenshot` files (theme-*.png)
-# land in a known place for the theme post-step below. KEEP[] are absolute
-# paths and subflows resolve relative to their flow file, so the cd is safe.
-cd "$FLOWS_DIR/.."
-
-set +e
 maestro --platform android test \
   -e CLERK_TEST_EMAIL="${CLERK_TEST_EMAIL}" \
   -e CLERK_TEST_PASSWORD="${CLERK_TEST_PASSWORD}" \
   -e CLERK_TEST_EMAIL_SECONDARY="${CLERK_TEST_EMAIL_SECONDARY:-}" \
   -e CLERK_TEST_PASSWORD_SECONDARY="${CLERK_TEST_PASSWORD_SECONDARY:-}" \
   "$@" \
   "${KEEP[@]}"
-maestro_rc=$?
-set -e
-
-# Verify theming on whatever screenshots the theming flows captured (Node
-# post-step; Maestro can't decode PNGs). A theme regression fails the run.
-"$SCRIPT_DIR/verify-themes.sh" || maestro_rc=1
-
-exit "$maestro_rc"

integration/mobile/flows/theming/dark-mode-applied.yaml

@@ -41,24 +41,10 @@ if [[ ${#KEEP[@]} -eq 0 ]]; then
   exit 0
 fi
 
-# Run maestro from integration/mobile so `takeScreenshot` files (theme-*.png)
-# land in a known place for the theme post-step below. KEEP[] are absolute
-# paths and subflows resolve relative to their flow file, so the cd is safe.
-cd "$FLOWS_DIR/.."
-
-set +e
 maestro --platform ios test \
   -e CLERK_TEST_EMAIL="${CLERK_TEST_EMAIL}" \
   -e CLERK_TEST_PASSWORD="${CLERK_TEST_PASSWORD}" \
   -e CLERK_TEST_EMAIL_SECONDARY="${CLERK_TEST_EMAIL_SECONDARY:-}" \
   -e CLERK_TEST_PASSWORD_SECONDARY="${CLERK_TEST_PASSWORD_SECONDARY:-}" \
   "$@" \
   "${KEEP[@]}"
-maestro_rc=$?
-set -e
-
-# Verify theming on whatever screenshots the theming flows captured (Node
-# post-step; Maestro can't decode PNGs). A theme regression fails the run.
-"$SCRIPT_DIR/verify-themes.sh" || maestro_rc=1
-
-exit "$maestro_rc"

integration/mobile/scripts/.gitignore

@@ -11,11 +11,12 @@ source "$SCRIPT_DIR/lib/filter-flows.sh"
 
 # Note: google-sso-from-forgot-password and sign-in-sign-out-sign-in were moved
 # to flows/native-side/ (they primarily exercise native auth UI, which the
-# clerk-ios/clerk-android suites own). They no longer run as part of the Expo
-# regression set. See flows/native-side/README.md.
+# clerk-ios/clerk-android suites own). The theming flows were removed entirely:
+# theme *delivery* is now verified deterministically by the config-plugin unit
+# test (src/__tests__/appPlugin.theme.test.js), and the color *render* is the
+# native SDKs' responsibility — no fragile screenshot pixel-check.
 REGRESSION_FLOWS=(
   "$FLOWS_DIR/sign-in/get-help-loop-regression.yaml"
-  "$FLOWS_DIR/theming/custom-theme-applied.yaml"
   "$FLOWS_DIR/smoke/cold-launch-no-flash.yaml"
 )