Add telemetry to diagnose intermittent macOS `test-go-pg` stalls and preserve timeout diagnostics.
- Log runner details at startup; sample load, swap, and `vm_stat` every second and `top` every 10 seconds to identify runner-wide pauses.
- Add stall detection to `cli` and `agent` `TestMain`, logging heap, GC, and goroutine counts when ticks arrive more than 5 seconds late.
- Run artifact uploads with `always() && !success()` so canceled test steps do not skip diagnostics.
- Add a `TEST_TIMEOUT` override: use 20m on macOS to leave room for goroutine dumps within the 30m job, retaining the 25m default for the nightly gauntlet.
Validated with race tests, binary compilation, `actionlint`, local macOS checks, and Makefile timeout checks.
Bobby Ho
dffa890d8f