The introspectable, fail-fast construction service (#157): a declarative,
replayable by-identifier op-script that builds a runnable blueprint through
validated ops and emits the #155 value, reusing the engine's existing gates
(no second validator, C24).
Surface-agnostic core = an eager/holistic gate split: the per-op-decidable
checks (name resolution, edge kind-match, the >1-cover DoubleWiredPort arm,
param bind) fire eagerly at the offending op; the only-at-end-decidable checks
(0-cover UnconnectedPort totality, DuplicateParamPath injectivity, root-role
boundness) stay holistic at finalize. Both cadences call the SAME extracted
predicates. Plus build-free introspection over the closed std_vocabulary
(enumerable companion) and a partial document's unwired slots. The JSON op-list
+ `aura graph build`/`introspect` CLI is a thin shell (iteration 2).
Spec auto-signed under /boss on a grounding-check PASS (11/11 load-bearing
current-behaviour assumptions ratified by named green tests). Derived sub-forks
logged on the issue.
refs #157
