323f0ba5

Created Started Finished

By: syd <syd@kronor.io>

Make test derivation outputs deterministic

nix build --rebuild reported the test derivations as possibly non-reproducible:
their output was Vitest stdout verbatim, which carries a wall-clock start time
and per-file durations. That defeats --rebuild and would defeat any
content-addressed early cutoff, since a rerun of unchanged tests produced a
different output hash every time.

The output is now a normalized summary: which files ran, how many assertions
passed, and the totals, with the timing dropped. All nineteen per-package test
derivations now pass --rebuild.

The machinery the two prototypes share moves to nix/support.nix.