fix(ci): stabilize release build test suites

[AlexMikhalev]

Summary

• make persistence_tests and selected_role_tests derive valid roles from the live CLI/config instead of hardcoding Default and Rust Engineer
• pass --features zlob to the nested cargo build inside terraphim_mcp_server integration tests when running under CI
• remove the remaining deterministic failures from the CI Main Branch release-build test step on current main

Verification

• cargo fmt
• cargo test -p terraphim_agent --test persistence_tests -- --nocapture
• cargo test -p terraphim_agent --test selected_role_tests -- --nocapture
• CI=true cargo test --release --target x86_64-unknown-linux-gnu -p terraphim_mcp_server --test integration_test --features zlob -- --nocapture
• CI=true cargo test --release --target x86_64-unknown-linux-gnu --workspace --features "self_update/signatures,zlob"