fix: correct paper-space grip projection and MTEXT attachment point rendering

- Grip points in paper space now use the 2-D linear to_px transform
  (tx/ty/ortho_size) instead of the 3-D view_proj matrix, matching the
  coordinate system used by PaperCanvas
- world_offset is no longer subtracted from paper-space entity grip
  positions — paper-space coordinates are already unoffset (same rule
  as wire tessellation in wires_for_block)
- MTEXT v_offset corrected for all attachment points: CXF glyphs sit
  on the baseline and extend upward, so Top attachment needs v_offset=-h,
  Bottom needs (n_lines-1)*line_h, Middle is the midpoint of the two

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/app/properties.rs

@@ -244,7 +244,10 @@ impl H7CAD {
     /// Rebuild the cached selected_grips from the current entity selection.
     pub(super) fn refresh_selected_grips(&mut self) {
         let i = self.active_tab;
-        let wo = self.tabs[i].scene.world_offset;
+        let is_paper = self.tabs[i].scene.current_layout != "Model";
+        // Paper-space entity coordinates are NOT offset by world_offset (same rule
+        // as wire tessellation in wires_for_block). Only subtract in model space.
+        let wo = if is_paper { [0.0f64; 3] } else { self.tabs[i].scene.world_offset };
         let (new_handle, new_grips) = {
             let selected = self.tabs[i].scene.selected_entities();
             if selected.len() == 1 {

src/app/update.rs

@@ -1,7 +1,7 @@
 use super::{H7CAD, Message, POLY_START_DELAY_MS};
 use super::helpers::{parse_coord, angle_close, ortho_constrain, polar_constrain, ucs_to_wcs, ucs_z_axis};
 use crate::scene::{self, Scene, VIEWCUBE_DRAW_PX, VIEWCUBE_PAD, VIEWCUBE_PX};
-use crate::scene::grip::{find_hit_grip, GripEdit};
+use crate::scene::grip::{find_hit_grip, find_hit_grip_paper, GripEdit};
 use crate::scene::object::GripApply;
 use crate::modules::ModuleEvent;
 use crate::ui::PropertiesPanel;
@@ -1362,8 +1362,20 @@ impl H7CAD {
 
                 if self.tabs[i].active_cmd.is_none() && !self.tabs[i].selected_grips.is_empty() {
                     if let Some(handle) = self.tabs[i].selected_handle {
-                        let vp_mat = self.tabs[i].scene.camera.borrow().view_proj(bounds);
-                        let grip_hit = find_hit_grip(p, &self.tabs[i].selected_grips, vp_mat, bounds);
+                        let is_paper = self.tabs[i].scene.current_layout != "Model";
+                        let grip_hit = if is_paper {
+                            let cam = self.tabs[i].scene.camera.borrow();
+                            let aspect = if vh > 0.0 { vw / vh } else { 1.0 };
+                            let half_h = cam.ortho_size();
+                            let half_w = half_h * aspect;
+                            let tx = cam.target.x;
+                            let ty = cam.target.y;
+                            drop(cam);
+                            find_hit_grip_paper(p, &self.tabs[i].selected_grips, tx, ty, half_w, half_h, bounds)
+                        } else {
+                            let vp_mat = self.tabs[i].scene.camera.borrow().view_proj(bounds);
+                            find_hit_grip(p, &self.tabs[i].selected_grips, vp_mat, bounds)
+                        };
                         if let Some((grip_id, is_translate, world)) = grip_hit {
                             self.tabs[i].active_grip = Some(GripEdit {
                                 handle,

src/app/view.rs

@@ -3,7 +3,7 @@ use super::document::DocumentTab;
 use super::history::history_dropdown_labels;
 use super::helpers::grid_plane_from_camera;
 use crate::scene::{VIEWCUBE_DRAW_PX, VIEWCUBE_PAD};
-use crate::scene::grip::grips_to_screen;
+use crate::scene::grip::{grips_to_screen, grips_to_screen_paper};
 use crate::scene::paper_canvas::PaperCanvas;
 use crate::scene::viewport_pane::{PaperViewportPane, ViewportPane};
 use crate::ui::overlay;
@@ -138,9 +138,21 @@ impl H7CAD {
                     let bounds = iced::Rectangle {
                         x: 0.0, y: 0.0, width: vw, height: vh,
                     };
-                    let vp_mat = tab.scene.camera.borrow().view_proj(bounds);
                     let sel_h = tab.selected_handle;
-                    grips_to_screen(&tab.selected_grips, vp_mat, bounds)
+                    let screen_grips = if is_paper {
+                        let cam = tab.scene.camera.borrow();
+                        let aspect = if vh > 0.0 { vw / vh } else { 1.0 };
+                        let half_h = cam.ortho_size();
+                        let half_w = half_h * aspect;
+                        let tx = cam.target.x;
+                        let ty = cam.target.y;
+                        drop(cam);
+                        grips_to_screen_paper(&tab.selected_grips, tx, ty, half_w, half_h, bounds)
+                    } else {
+                        let vp_mat = tab.scene.camera.borrow().view_proj(bounds);
+                        grips_to_screen(&tab.selected_grips, vp_mat, bounds)
+                    };
+                    screen_grips
                         .into_iter()
                         .filter(|(_, screen, _, _)| {
                             screen.x.is_finite()