- Gate model/value heuristic output behind --verbose/-v flag (quiet by default)
- Add wireviz>=0.4 as dev dependency for roundtrip render tests
- Generate SVG/PNG diagram renders for inter_module, single_module, hierarchical
- Embed rendered diagrams in README with layout optimization callout
C1: Port count mismatch now emits ERROR to stderr and marks
unconnected ports as __UNCONNECTED_<name>__ (never silent)
C2: Single-module pin mapping built in lockstep — cable_wires
always matches header_pins length, warns on unmappable nets
C3: VSS removed from is_power_net (it's ground per CMOS convention),
dead _POWER_PATTERN regex replaced with _KNOWN_NET_PATTERN
C4: apply_filters dead computation removed, docstring clarifies
that net-level filtering is a mapper concern
I3: WireViz render catches (ValueError, TypeError, OSError) with
diagnostic context instead of bare Exception
I5: Invalid --format flags now warn and error instead of silently
falling through to defaults
I6: Model/value heuristic warns on stderr when it triggers, since
signal names like ALERT or DATA could be misidentified
New tests: VSS classification, port count mismatch (C1), model/value
heuristic warning (I6), duplicate refs (S3), empty subcircuit (S2),
full pipeline determinism across 3 runs (S1)
115 tests pass, ruff clean
