param_space()/derive_signature project each frame's gang table: member
addresses are skipped, the gang's single public address (prefixed like any
knob at that frame) is emitted once at its FIRST member's raw position — so
every consumer of param_space (binders, grids, campaign axes, --list-axes,
registry coverage) inherits the gang with zero changes.
compile_with_cells expands the public point back onto the raw layout via
expansion_map (the collect_params mirror walk): a gang's cell is duplicated
into every member slot, un-ganged slots pass through. For a gang-free
blueprint the map is the identity and behaviour is byte-identical; the
lower_items cursor walk and all build closures are untouched.
The load-bearing equivalence is pinned in-module (ganged compile == the
member-bound un-ganged twin, bit-identical wiring and run output) and again
from OUTSIDE the crate in tests/gang_e2e.rs — the C24 consumer seam a
project crate or the World actually uses.
Verified: cargo test -p aura-engine 253/0 lib + 5/0 gang_e2e (all groups
green), workspace clippy -D warnings clean. RED-first evidenced by the loop
via temporary call-site reversion (all 4 new tests failed for the expected
reason, then the implementation was restored).
refs #61
