Fix TestFlight workflow temp paths

[enaboapps]

Summary

• remove job-level runner.temp expressions that make the workflow invalid
• resolve archive, export, verification, and cleanup paths from RUNNER_TEMP inside shell steps

Tracks #90.

Validation

• git diff --check
• Node 24 npm run validate (43 suites / 312 tests; Expo Doctor 21/21)
• GitHub workflow dispatch parser failure reproduced before the fix

[enaboapps]

Independent latest-head review completed for 4be9af4: no actionable findings. The review confirmed that the invalid job-level context references are removed and archive, export, verification, artifact, and cleanup paths consistently use quoted RUNNER_TEMP locations.