merge: TEXTEDIT command + TEXTEDITMODE sysvar (#130)

Merge PR #130 (KarimJerbi) and resolve review findings:

- Conflict (settings.rs): keep current persisted-settings layout, append
  texteditmode field.
- Conflict (command/mod.rs): keep both new CmdResult variants — main's
  live-entity ops and the PR's text-edit suspend/resume.
- Bug: invalid TEXTEDITMODE value no longer aborts via the Measurement
  arm; it now re-prompts with the error and stays active.
- Dedup: single parse_texteditmode() helper replaces the value parsing
  duplicated across commands.rs, settings.rs and textedit.rs.
- Strip trailing whitespace.

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

src/app/commands.rs

@@ -1444,6 +1444,22 @@ impl OpenCADStudio {
                 self.tabs[i].active_cmd = Some(Box::new(new_cmd));
             }
 
+            "TEXTEDIT" | "TEDIT" => {
+                use crate::modules::annotate::textedit::TexteditCommand;
+                let mode_str = if self.texteditmode { "Single" } else { "Multiple" };
+                self.command_line.push_output(&format!("Current settings: Edit mode = {}", mode_str));
+                let new_cmd = TexteditCommand::new(self.texteditmode);
+                self.command_line.push_info(&new_cmd.prompt());
+                self.tabs[i].active_cmd = Some(Box::new(new_cmd));
+            }
+
+            "TEXTEDITMODE" => {
+                use crate::modules::annotate::textedit::TexteditmodeCommand;
+                let cmd = TexteditmodeCommand::new(self.texteditmode);
+                self.command_line.push_info(&cmd.prompt());
+                self.tabs[i].active_cmd = Some(Box::new(cmd));
+            }
+
             "DIMALIGNED" | "DAL" => {
                 use crate::modules::annotate::aligned_dim::AlignedDimensionCommand;
                 let cmd = AlignedDimensionCommand::new();
@@ -4942,6 +4958,23 @@ impl OpenCADStudio {
                     );
                 }
             }
+            cmd if cmd.starts_with("TEXTEDITMODE ") => {
+                let val_str = cmd.trim_start_matches("TEXTEDITMODE").trim().to_lowercase();
+                if val_str.is_empty() {
+                    let v = if self.texteditmode { 1 } else { 0 };
+                    self.command_line.push_output(&format!("TEXTEDITMODE = {v}"));
+                } else if let Some(v) =
+                    crate::modules::annotate::textedit::parse_texteditmode(&val_str)
+                {
+                    self.texteditmode = v;
+                    let n = if v { 1 } else { 0 };
+                    self.command_line
+                        .push_output(&format!("TEXTEDITMODE set to {n}"));
+                } else {
+                    self.command_line
+                        .push_error("Requires 0 OR 1 OR MULTIPLE OR SINGLE");
+                }
+            }
             cmd if cmd == "PDSIZE" || cmd.starts_with("PDSIZE ") => {
                 let val_str = cmd.trim_start_matches("PDSIZE").trim();
                 if val_str.is_empty() {