Update NoApproximation API

src/bilinear_approximations/no_approx.jl

@@ -47,3 +47,54 @@ function _add_bilinear_approx!(
     end
     return result_expr
 end
+
+"""
+    _add_bilinear_approx!(::NoBilinearApproxConfig, container, C, names, time_steps, xsq, ysq, x_var, y_var, x_bounds, y_bounds, meta)
+
+Precomputed-form no-op bilinear approximation: returns exact x·y as a QuadExpr.
+`xsq` and `ysq` are accepted for signature parity with the precomputed-form
+dispatches of `Bin2Config` and `HybSConfig` (so a caller can swap configs
+without changing the call site) but are unused here.
+
+# Arguments
+- `::NoBilinearApproxConfig`: no-op configuration (no fields)
+- `container::OptimizationContainer`: the optimization container
+- `::Type{C}`: component type
+- `names::Vector{String}`: component names
+- `time_steps::UnitRange{Int}`: time periods
+- `xsq`: precomputed x² container (ignored)
+- `ysq`: precomputed y² container (ignored)
+- `x_var`: container of x variables indexed by (name, t)
+- `y_var`: container of y variables indexed by (name, t)
+- `x_bounds::Vector{MinMax}`: per-component bounds on x
+- `y_bounds::Vector{MinMax}`: per-component bounds on y
+- `meta::String`: variable type identifier for the approximation
+"""
+function _add_bilinear_approx!(
+    ::NoBilinearApproxConfig,
+    container::OptimizationContainer,
+    ::Type{C},
+    names::Vector{String},
+    time_steps::UnitRange{Int},
+    xsq,
+    ysq,
+    x_var,
+    y_var,
+    x_bounds::Vector{MinMax},
+    y_bounds::Vector{MinMax},
+    meta::String,
+) where {C <: IS.InfrastructureSystemsComponent}
+    result_expr = add_expression_container!(
+        container,
+        BilinearProductExpression,
+        C,
+        names,
+        time_steps;
+        meta,
+        expr_type = JuMP.QuadExpr,
+    )
+    for name in names, t in time_steps
+        result_expr[name, t] = x_var[name, t] * y_var[name, t]
+    end
+    return result_expr
+end