fix(cli): simplify update commands and project package loading

[bigfish1913]

Summary

• make rpi update update only installed Rust-native extensions
• make rpi pi-update update only configured Pi npm/Git packages
• preserve rpi CLI self-update as rpi self-update
• keep rpi package update as the compatibility entry point for both families
• load project .rpi/.pi resources and packages without interactive confirmation
• keep --no-approve and /trust no as explicit opt-out controls
• allow project Pi package operations without a pre-existing trust record
• update startup notices, help text, documentation, and tests

Verification

• cargo test -p rpi-cli --locked (457 unit tests plus package gate integration test)
• cargo check -p rpi-cli --all-targets --locked
• cargo fmt --all
• git diff --check