CDSL Bridge: Mounting Plate

Use for a mostly uniform plate, base, adapter, fixture, or panel.
Invariants: a named rectangular/rounded profile, thickness, datum-based holes, and functional cutouts.
Plan: extrude_add_blind base -> hole_wizard or cut-hole features -> pattern_linear/pattern_mirror -> slots and pockets -> late fillet/chamfer only with selectors.
Prefer rectangle, rectangle_with_fillets, or obround profiles. Keep edge margins and pitch as named numeric parameters.
Rectangular hole groups use linear/mirror patterns; never use circular-pattern semantics for a plate.