The compile core. resolve_tap_wire resolves a blueprint Tap's interior
{node, field} through the lowering table exactly as OutField re-exports and
edges resolve — a leaf to its remapped index (output-arity checked), a nested
composite through its output remap. Taps are terminal (not re-exported through
the boundary): a flat_taps accumulator threads through the lowering recursion,
so an interior composite's taps hoist to the root FlatGraph.taps with remapped
wires — the case the CLI single-run wrapper relies on. validate_wiring gains a
tap leg (threaded at all three call sites incl. GraphSession::finish) and
CompileError::TapWireOutOfRange names a bad wire. Root-resolve, out-of-arity,
and nested-hoist are pinned green.
refs #282
Second slice: the resolved-tap carrier. FlatTap { name, node, field } is the
output-side twin of SourceSpec — its name survives compile, load-bearing for
by-name binding (#275). FlatGraph gains a taps field, threaded (empty) through
every construction site the compiler enumerates. Bootstrap ignores it (taps
materialize as real recorder nodes/edges before bootstrap in a later slice).
Purely additive: the inert-producer pin and full suite stay green.
refs #282
claude