feat: Implement in-place MText editor with formatting toolbar and live preview

- Added SVG icons for text formatting options (bold, italic, underline, overline, strike, uppercase, lowercase).
- Introduced a new `MTextEditorState` struct to manage the state of the MText editor.
- Implemented functionality to open the MText editor from the command line and edit existing MText entities.
- Added message handling for various MText editor actions (formatting, height, style, font, justification, alignment, line spacing).
- Created a dedicated preview area for MText rendering within the editor.
- Updated the command structure to support opening the MText editor and handling text input.
- Refactored existing MText command logic to integrate with the new editor.

src/modules/annotate/mtext.rs

@@ -1,6 +1,3 @@
-use acadrust::types::Vector3;
-use acadrust::{EntityType, MText};
-
 use crate::command::{CadCommand, CmdResult};
 use crate::modules::{IconKind, ModuleEvent, ToolDef};
 use crate::scene::wire_model::WireModel;
@@ -19,7 +16,6 @@ pub fn tool() -> ToolDef {
 
 enum Step {
     InsertPoint,
-    WaitText(Vec3),
 }
 
 pub struct MTextCommand {
@@ -42,16 +38,17 @@ impl CadCommand for MTextCommand {
     fn prompt(&self) -> String {
         match &self.step {
             Step::InsertPoint => "MTEXT  Specify insertion point:".into(),
-            Step::WaitText(pos) => format!(
-                "MTEXT  Type text, press Enter  [at {:.2},{:.2}]:",
-                pos.x, pos.z
-            ),
         }
     }
 
     fn on_point(&mut self, pt: Vec3) -> CmdResult {
-        self.step = Step::WaitText(pt);
-        CmdResult::NeedPoint
+        // Hand off to the in-place editor (toolbar + text area + live preview).
+        CmdResult::OpenMTextEditor {
+            pos: pt,
+            handle: None,
+            initial: String::new(),
+            height: 0.25,
+        }
     }
 
     fn on_enter(&mut self) -> CmdResult {
@@ -61,32 +58,6 @@ impl CadCommand for MTextCommand {
         CmdResult::Cancel
     }
 
-    fn wants_text_input(&self) -> bool {
-        matches!(self.step, Step::WaitText(_))
-    }
-
-    fn wants_text_with_spaces(&self) -> bool {
-        matches!(self.step, Step::WaitText(_))
-    }
-
-    fn on_text_input(&mut self, text: &str) -> Option<CmdResult> {
-        if let Step::WaitText(pos) = &self.step {
-            if text.trim().is_empty() {
-                return Some(CmdResult::Cancel);
-            }
-            let mt = MText {
-                insertion_point: Vector3::new(pos.x as f64, pos.y as f64, pos.z as f64),
-                value: text.to_string(),
-                height: 0.25,
-                rectangle_width: text.len() as f64 * 0.15,
-                ..Default::default()
-            };
-            Some(CmdResult::CommitEntity(EntityType::MText(mt)))
-        } else {
-            None
-        }
-    }
-
     fn on_mouse_move(&mut self, _pt: Vec3) -> Option<WireModel> {
         None
     }