Dimensional constraints: DCFORM, DIMCONSTRAINT options, -PARAMETERS, value prompt, save without display overrides

DCFORM sets the annotational or dynamic form and continues into the
DIMCONSTRAINT option prompt, whose wording and last-used default match the
reference. -PARAMETERS manages parameters from the command line; a
double-clicked constraint dimension opens its value prompt. Dynamic
dimensions rescale on every camera change and their display overrides stay
out of the saved file. A driving dimension between an entity's own ends no
longer has its length retained, so a new value moves the second point along
the dimension axis; parameter edits hold the first constraint point.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

src/scene/mod.rs

@@ -2302,9 +2302,8 @@ pub struct Scene {
     pub dynamic_constraint_display: bool,
     /// Dynamic dimensions DCHIDE or DYNCONSTRAINTDISPLAY 0 keep off screen.
     hidden_dynamic_dimensions: HashSet<Handle>,
-    /// The zoom band (`quantize_wpp`) the dynamic dimensions were last
-    /// scaled for; 0 until the first scaling.
-    dynamic_dimension_band: f32,
+    /// The camera generation the dynamic dimensions were last scaled for.
+    dynamic_dimension_camera_gen: Option<u64>,
     /// Session-only visibility overrides for constraint glyphs.
     hidden_parametric_constraints: HashSet<(
         parametric_constraints::ParametricScope,
@@ -2638,7 +2637,7 @@ impl Scene {
             constraint_name_format: 2,
             dynamic_constraint_display: true,
             hidden_dynamic_dimensions: HashSet::default(),
-            dynamic_dimension_band: 0.0,
+            dynamic_dimension_camera_gen: None,
             hidden_parametric_constraints: HashSet::default(),
             shown_parametric_constraints: HashSet::default(),
             named_parameters: named_parameters::ParameterTable::new(),