fix: resolve Android runtime from PAM releases

[DavidWilliamBalbino]

Summary

• stop deriving PAM runtime release tags from the independently versioned Native SDK
• resolve the verified Android bundle through the PAM stable release channel
• preserve explicit mirror URLs and normalize trailing slashes
• bump the Native SDK contract to 0.8.2

Public failure reproduced

pam runtime:install . from PAM 2.0.10 / Native 0.8.1 requested push-in/pam/releases/download/v0.8.1/pam-android-runtime.tar.gz and received 404.

Validation

• all 26 pam-native-cli tests pass
• PHP SDK suite passes on PAM PHP 8.5.9
• end-to-end download from releases/latest/download, SHA-256 verification, extraction and installation succeeded
• doctor reports both PHP 8.5 Android ABIs and both prebuilt Native engines as [ok]