feat: simplify PAM Native project startup

[DavidWilliamBalbino]

Summary

• forward pam serve and pam start to the canonical pam dev flow inside Native projects
• retain server semantics for API, Laravel, and raw projects
• consume PAM Native 0.8.3 across release and validation workflows
• release PAM 2.0.12

Validation

• PAM_NATIVE_HOME=/tmp/pam-native-zero-setup cargo test --bin pam (102 passed)
• cargo +1.88.0 fmt --all -- --check
• git diff --check
• PAM Native PR docs: prepare pam-skeleton 2.0.1 release #74: all Rust/PHP, Android 26/36, Swift/UIKit, and accessibility checks passed