proper modelica text model editing

BEdit/AGENTS.md

@@ -104,6 +104,11 @@ Keep the root of `src/bedit` minimal. New UI modules should go into the relevant
   named BEdit `$name$` macro completions editable there; arbitrary `$name$`
   expressions are highlighted as BEvalues. Highlight colors and bold/italic
   styles are persisted under `syntax/<category>/` in application settings.
+- Text component sources may contain private Modelica declarations in
+  `source.declarations`. The text-definition editor exposes declarations above
+  `source.initialEquations` and `source.equations`, with the same highlighting
+  and completion in all three fields. The composer emits each in its matching
+  Modelica section.
 - Application-wide messages use `core.application_log.get_logger()`. The main
   window installs the Qt log-panel handler; core code must only use standard
   Python logging and must not import the GUI handler.
@@ -116,6 +121,8 @@ Keep the root of `src/bedit` minimal. New UI modules should go into the relevant
   per component instance from graph connections and exposed while compiling as
   `$portname_N$`; array connection endpoints receive stable one-based indices in
   graph connection order.
+- Simulation → Export Model composes through `Simulation.compose_source()` without
+  building the model, then writes the generated source as a `.mo` file.
 - OpenModelica integration belongs in `core/simulation/openmodelica.py`. Its
   persistent worker and OMC session start lazily on the first queued request.
   Never perform OMPython work directly on the Qt GUI thread. Result and error