fix(dashboard): derive api Services latency_url from api_http_addr (closes #164)

[kiannidev]

Summary

• Add Config::api_status_url() in genie-common → http://{api_http_addr()}/api/status.
• Dashboard dashboard_service_targets() uses api_status_url() for the api row instead of raw [services.api].url (core already uses core_health_url() from [services.core].url drifts from [core].port — health monitor and dashboard probe wrong port #121).
• Unit tests for bare-authority TOML (127.0.0.1:4080/api/status) and dashboard target URL.

Closes #164

Real Behavior Proof

• I have built and run the affected code locally (or noted why I could not).
• I have verified the change end-to-end on Jetson hardware OR explained the equivalent verification path I used.

What I ran

cargo test -p genie-common api_status_url
cargo test -p genie-api dashboard_api_target
cargo fmt --all -- --check

What I observed

All tests passed. With [services.api].url = "127.0.0.1:4080/api/status", dashboard latency probe uses http://127.0.0.1:4080/api/status instead of the raw TOML string.

Test plan

• cargo test -p genie-common api_status_url
• cargo test -p genie-api dashboard_api_target dashboard_core_target
• cargo fmt --all -- --check
• Optional: dev TOML with custom API port, curl dashboard /api/services, api row healthy when genie-api listens