fix(pasteblock): place the block at the picked point

The pasted block is defined around the clipboard base, so its origin
is already that point, but the insertion still subtracted the base and
landed the block offset from the pick. The base now only positions the
world-space preview, and it stays f64.

Fixes #1731

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/modules/insert/insert_block.rs

@@ -15,7 +15,7 @@ use crate::t;
 use codec::entities::{AttributeDefinition, AttributeEntity, Entity, Insert};
 use codec::types::Vector3;
 use codec::EntityType;
-use glam::{DVec3, Vec3};
+use glam::DVec3;
 
 use crate::app::settings::BlockInsertOptions;
 use crate::command::{CadCommand, CmdResult, DynField, InputKind, WorkingPlane};
@@ -130,6 +130,10 @@ pub struct InsertBlockCommand {
     /// through the same base-point convention the render path uses, so the
     /// host injects it when it resolves the block's ATTDEFs.
     block_base: Vector3,
+    /// Where the preview wires' block origin sits: zero for wires taken from
+    /// the definition, the clipboard base for paste-as-block, whose preview
+    /// is the clipboard in world coordinates.
+    preview_origin: DVec3,
 }
 
 impl InsertBlockCommand {
@@ -157,6 +161,7 @@ impl InsertBlockCommand {
             pending_insert: None,
             plane: WorkingPlane::default(),
             block_base: Vector3::ZERO,
+            preview_origin: DVec3::ZERO,
         }
     }
 
@@ -219,12 +224,13 @@ impl InsertBlockCommand {
         command
     }
 
-    /// Paste-as-block: the block is placed at the picked point.
-    pub fn new_for_block(name: String, preview_wires: Vec<WireModel>, base: Vec3) -> Self {
+    /// Paste-as-block: the block is placed at the picked point. The block
+    /// was defined around `base`, so its origin is the clipboard base.
+    pub fn new_for_block(name: String, preview_wires: Vec<WireModel>, base: DVec3) -> Self {
         let mut command = Self::base_state(Mode::Paste, Self::single_picker(&name));
         command.name = name;
         command.preview = preview_wires;
-        command.base = base.as_dvec3();
+        command.preview_origin = base;
         command.preset_scale = [Some(1.0); 3];
         command.preset_rotation = Some(0.0);
         command.step = Step::Point;
@@ -822,7 +828,7 @@ impl CadCommand for InsertBlockCommand {
             self.preset_scale[2].unwrap_or(1.0),
         ];
         let (sin, cos) = self.preset_rotation.unwrap_or(0.0).sin_cos();
-        let base = self.base;
+        let base = self.preview_origin + self.base;
         let origin = self.plane.to_local(pt);
         let plane = self.plane;
         self.preview