harness.toml loading via a stdlib-only TOML subset parser (tables, bare
keys, strings/ints/bools, multi-line arrays; anything richer fails loudly).
Secrets are refs only (env:/file:/literal:, bw: reserved) and are redacted
from every error path. Model routing v0: static class -> tier alias ->
concrete model map per the DESIGN model-selection layer; requests carry the
resolved concrete model and unknown classes fail hard so routing stays
auditable. Table-driven tests cover the parser, validation, key refs, and
routing decisions.
💘 Generated with Crush
Assisted-by: Crush:glm-5.2
