[FEATURE] Add support for custom properties in the JUnit report files

[zcsteele]

Problem Statement

The official Maestro docs covers a map named 'Properties' in the flow configuration section which can be used to define custom properties stored in the JUnit XML report files (https://docs.maestro.dev/maestro-flows/workspace-management/test-reports-and-artifacts#custom-properties). The current implementation of maestro-runner does not process this map, effectively ignoring it during execution.

Proposed Solution

The YAML parser and test report engine should be updated to parse this key from the flow header and include the custom properties in the relevant JUnit report files.

Use Case

For my purposes, I would like to use the 'Properties' map to associate each flow file with a specific test ID in our test tracking system.

Example

sample.yaml:

properties:
  testID: Test-1234
---
- launchApp: com.google.android.deskclock

junit-report.xml:

<?xml version="1.0" encoding="UTF-8"?>
<testsuites tests="1" failures="0" skipped="0" errors="0" time="2.074">
  <testsuite name="maestro-runner" tests="1" failures="0" skipped="0" errors="0" time="2.074" timestamp="2026-05-14T12:52:42-07:00">
    <testcase name="demo-runner-junit" classname="demo-runner-junit" time="2.060">
      <properties>
        <property name="file" value="sample.yaml"/>
        <property name="device.name" value="google sdk_gphone64_arm64"/>
        <property name="device.id" value="emulator-5554"/>
        <property name="device.platform" value="android"/>
        <property name="testID" value="Test-1234"/>
      </properties>
    </testcase>
  </testsuite>
</testsuites>

[omnarayan]

We already adding these values by default, we see about adding this