Add configurable OpenSearch feature and UI improvements

- Add MIT license with Austin Godber copyright
  - Implement optional OpenSearch feature toggle via EMBEDDINGBUDDY_OPENSEARCH_ENABLED
  - Disable OpenSearch by default in production for security
  - Add development environment flag to test OpenSearch disable state
  - Update about modal to open by default with improved content
  - Reorganize text input component: move model selection below text input
  - Conditionally show/hide OpenSearch tab and callbacks based on configuration
  - Update tooltips to reflect OpenSearch availability status

src/embeddingbuddy/ui/components/textinput.py

@@ -16,14 +16,14 @@ class TextInputComponent:
         """Create the complete text input interface with model selection and processing options."""
         return html.Div(
             [
-                # Model selection section
-                self._create_model_selection(),
-                html.Hr(),
                 # Text input section
                 self._create_text_input_area(),
                 # Text action buttons
                 self._create_text_action_buttons(),
                 html.Hr(),
+                # Model selection section
+                self._create_model_selection(),
+                html.Hr(),
                 # Processing options
                 self._create_processing_options(),
                 html.Hr(),