Settled-source direct entry from issue #54 (no brainstorm). Retire the
hand-rolled RunReport::to_json writer and render stdout through serde, so a
record's stdout JSON is byte-identical to its runs.jsonl line, and pin that
identity with a test. Removes the last hand-rolled RunReport JSON writer
(amended C16). Disk shape unchanged; graph-model JSON (model_to_json) out of
scope (#58/#28).
Auto-signed under /boss spec_auto_sign: objective gates green (precondition
clean, self-review clean, grounding-check PASS) + unanimous 5-lens spec-skeptic
panel (criterion/grounding/scope-fork/ambiguity/plan-readiness all SOUND). The
grounding juror re-ran serde_json 1.0.150 against the canonical-form fixture and
confirmed the spec's "After" bytes. The one C16-scrutinized consequence
(serde_json dev-dep -> normal dep in aura-engine) is named and justified in the
spec; scope-fork juror confirmed it is settled by amended C16, not a silent pick.
refs #54
Brummel
c8634d7fa9