Replace the hardcoded test harness main() with a generated static registry
and index-based accessors, and move all reporting into runtime/eltest.el.
The old harness inlined direct calls into main() and counted assertions in
two globals. That shape cannot report which test failed, how long any test
took, or whether a test ran at all -- a misspelled registration reported
success for a test that never executed.
- assertions record into per-test state instead of global counters
- registry table emitted at compile time; discovery strictly precedes
execution, which is what later enables --list, filtering and sharding
- per-test wall timing on CLOCK_MONOTONIC, taken in C around the call
- runner in El: structured NDJSON events as source of truth, human output
rendered from the same fields
Neuron