Rename the project to FieldCraft

Crates fieldcraft-*, binaries fieldcraft and fieldcraft-cli, the .fieldcraft file (format tag
fieldcraft/1, manifest fieldcraft.json), FIELDCRAFT_* environment variables, the MCP server
name, egui widget ids (fc_*), the app icon document FieldCraft.icon and its generated family,
docs and licences. No compatibility shim: no files of the earlier name exist.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01NmAttHhUZTokgPeEJia8sm

crates/ui-egui/src/capture.rs

@@ -292,7 +292,7 @@ impl Canvas {
 
 #[cfg(test)]
 mod tests {
-    use modelcraft_engine::Session;
+    use fieldcraft_engine::Session;
 
     use super::*;
 
@@ -331,7 +331,7 @@ mod tests {
     #[test]
     fn the_whole_window_is_captured_with_panels_and_viewport() {
         let mut app = ModelApp::new(Session::default());
-        app.run_script(&modelcraft_engine::sample::script()).unwrap();
+        app.run_script(&fieldcraft_engine::sample::script()).unwrap();
         let image = app.capture(size(900.0, 600.0)).unwrap();
         assert_eq!(image.size, [900, 600]);
         let t = Tokens::dark();