feat(f64): command layer compiles on DVec3

Whole command/snap/grip/cursor chain now builds on f64 DVec3 end to end,
so picked points, snaps and grip drags stay precise at UTM-scale
coordinates instead of quantizing to ~0.5 m through f32.

- All ~80 command files migrated: draw (line/circle/arc/ellipse/shapes
  in full f64; others via point methods), modify, annotate, insert, view,
  inquiry, layers, groups, clipboard, layout.
- Entity apply_grip impls updated for GripApply::{Absolute,Translate}(DVec3).
- Construction sites (EntityTransform/CmdResult/DynAnchor) emit DVec3;
  wire-preview boundaries cast to f32 only at the GPU edge.
- Modify/annotate commands keep internal Vec3 geometry where precision is
  non-critical, casting at the DVec3 boundary; key draw commands store f64.

Builds clean (no warnings). Visual verification of crosshair/snap/grip at
extreme UTM zoom pending.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/app/automation.rs

@@ -422,7 +422,7 @@ impl OpenCADStudio {
                 if let Some(r) = self.tabs[i]
                     .active_cmd
                     .as_mut()
-                    .map(|c| c.on_entity_pick(handle, pt))
+                    .map(|c| c.on_entity_pick(handle, pt.as_dvec3()))
                 {
                     let _ = self.apply_cmd_result(r);
                 }
@@ -436,7 +436,7 @@ impl OpenCADStudio {
                 }
             }
             self.last_point = Some(pt);
-            if let Some(r) = self.tabs[i].active_cmd.as_mut().map(|c| c.on_point(pt)) {
+            if let Some(r) = self.tabs[i].active_cmd.as_mut().map(|c| c.on_point(pt.as_dvec3())) {
                 let _ = self.apply_cmd_result(r);
             }
         } else if let Some(r) = self.tabs[i]

src/app/commands.rs

@@ -5402,7 +5402,7 @@ impl OpenCADStudio {
                 if selected.len() == 1 {
                     let handle = selected[0].0;
                     let mut cmd = ExtrudeCommand::new(color);
-                    cmd.on_entity_pick(handle, glam::Vec3::ZERO);
+                    cmd.on_entity_pick(handle, glam::DVec3::ZERO);
                     self.command_line.push_info(&cmd.prompt());
                     self.tabs[i].active_cmd = Some(Box::new(cmd));
                 } else {
@@ -5931,7 +5931,7 @@ impl CadCommand for DrawOrderRefCommand {
     fn on_entity_pick(
         &mut self,
         handle: acadrust::Handle,
-        _pt: glam::Vec3,
+        _pt: glam::DVec3,
     ) -> crate::command::CmdResult {
         if handle.is_null() {
             return crate::command::CmdResult::NeedPoint;
@@ -5941,7 +5941,7 @@ impl CadCommand for DrawOrderRefCommand {
         crate::command::CmdResult::Relaunch(cmd, std::mem::take(&mut self.to_move))
     }
 
-    fn on_point(&mut self, _pt: glam::Vec3) -> crate::command::CmdResult {
+    fn on_point(&mut self, _pt: glam::DVec3) -> crate::command::CmdResult {
         crate::command::CmdResult::NeedPoint
     }
 

src/app/plugin_host.rs

@@ -232,7 +232,7 @@ impl crate::command::CadCommand for PluginInteractiveAdapter {
         crate::plugin::guard("InteractiveCommand::prompt", || self.inner.prompt())
             .unwrap_or_default()
     }
-    fn on_point(&mut self, pt: glam::Vec3) -> crate::command::CmdResult {
+    fn on_point(&mut self, pt: glam::DVec3) -> crate::command::CmdResult {
         crate::plugin::guard("InteractiveCommand::on_point", || {
             self.inner.on_point([pt.x as f64, pt.y as f64, pt.z as f64])
         })
@@ -250,7 +250,7 @@ impl crate::command::CadCommand for PluginInteractiveAdapter {
         })
         .unwrap_or(false)
     }
-    fn on_entity_pick(&mut self, handle: Handle, pt: glam::Vec3) -> crate::command::CmdResult {
+    fn on_entity_pick(&mut self, handle: Handle, pt: glam::DVec3) -> crate::command::CmdResult {
         crate::plugin::guard("InteractiveCommand::on_object_pick", || {
             self.inner
                 .on_object_pick(handle, [pt.x as f64, pt.y as f64, pt.z as f64])

src/app/view.rs

@@ -270,7 +270,7 @@ impl OpenCADStudio {
                 // A command may drive a typed scalar by mouse (e.g. a
                 // perpendicular distance to a picked object); show that live
                 // value in the box until the user types over it.
-                let live = tab.active_cmd.as_ref().and_then(|c| c.dyn_live_value(w));
+                let live = tab.active_cmd.as_ref().and_then(|c| c.dyn_live_value(w.as_dvec3()));
                 let boxes: Vec<overlay::DynBox> = tab
                     .dyn_fields
                     .iter()