fix(preview): use project scheme instead of slug for dev-build QR codes

[romainlq]

Problem

When using the preview action with qr-target: dev-build, the generated QR code uses the project's slug instead of the custom scheme defined in app.config.ts.

This causes issues when multiple app variants (dev, staging, production) share the same slug but have different scheme values — a common setup for teams testing multiple environments on the same device.

Current behavior:
// app.config.ts
{ slug: "myapp", scheme: "myappdev" }
// QR code generates: exp+myapp://expo-development-client/...Expected behavior:
// app.config.ts
{ slug: "myapp", scheme: "myappdev" }
// QR code generates: myappdev://expo-development-client/...## Solution

• Rename appSlug parameter to appScheme in getUpdateGroupQr() for clarity
• Pass the actual scheme (with fallback to slug) instead of the slug in getVariables()
• Apply the same fix to continuous-deploy-fingerprint action

Changes

File	Change
src/eas.ts	Renamed appSlug → appScheme parameter
src/actions/preview.ts	Use scheme with slug fallback
src/actions/continuous-deploy-fingerprint.ts	Use scheme with slug fallback
src/__tests__/eas.test.ts	Updated test parameters
src/__tests__/actions/preview.test.ts	Added tests for scheme selection + updated snapshot

Testing

With a project using slug: "froot" and scheme: "frootdev":

	QR code scheme
Before fix	exp+froot://... ❌
After fix	frootdev://... ✅

Unit tests added to verify scheme selection behavior.

New unit tests cover:

• ✅ Custom scheme is used when defined
• ✅ Falls back to slug when no scheme is defined
• ✅ Falls back to slug when scheme array is empty
• ✅ expo-go target doesn't include appScheme
• ✅ Single string scheme is supported

[romainlq]

Hi, any update on this one ?