feat: download compatible EAS development builds

[janicduplessis]

Description

Expo projects using EAS development builds can now select them with stim ios --eas-profile <name> or stim android --eas-profile <name>. A missing compatible build stops with the EAS command to run; Stim never starts a potentially billable cloud build or falls back to local compilation.

Solution

EAS CLI resolves the selected profile and native fingerprint, then downloads or reuses its cached artifact. Stim coordinates downloads by EAS project/build ID and uses the returned artifact directly for its existing installation, Metro and launch checks.

Internal development builds work on simulators, emulators and connected physical devices. iOS device artifacts must admit the target UDID in a valid provisioning profile and provide a development-client URL scheme. Provisioning failures point to EAS device registration and rebuilding commands; Stim does not change signing accounts. Release profiles and local build selectors are refused.

EAS fingerprint generation uploads fingerprint metadata. Metro continues using the local environment. Both behaviors are documented in stim guide lifecycle eas.

Test plan

• Live Trailhead validation: cache miss without building, then an explicitly approved EAS simulator build, download and successful launch with clean logs. A repeat run reused EAS's cached artifact and skipped unchanged installation; EAS CLI confirmed Using cached build.
• Hardware installation and launch remain unverified. Physical-device tests cover signed-app provisioning gates, EAS registration/rebuild remedies, unchanged signatures, Android APK installation and argument validation before EAS calls.
• Regression coverage also exercises profile environments, Debug overrides, fingerprint/target mismatches, missing builds, failed EAS calls, download claims and retry guidance that preserves the selected device.
• All repository checks pass, including 4,297 unit tests and 84 end-to-end tests. Real EAS CLI config, fingerprint, list and download invocations were exercised against Trailhead.

Fixes #759