Extract inline styles to .razor.css files for grids

Moved CSS from inline <style> blocks in CatalogsGrid.razor and MassDataGrid.razor to dedicated CatalogsGrid.razor.css and MassDataGrid.razor.css files. This improves maintainability and keeps styling concerns separate from component logic. No changes to the actual styles were made.

DbFirst.BlazorWebApp/Components/CatalogsGrid.razor

@@ -2,54 +2,6 @@
 @inject LayoutApiClient LayoutApi
 @inject IJSRuntime JsRuntime
 
-<style>
-    .action-panel { margin-bottom: 16px; }
-    .grid-section { margin-top: 12px; }
-    .catalog-edit-popup {
-        min-width: 720px;
-    }
-    .band-editor {
-        display: grid;
-        gap: 12px;
-        margin-bottom: 16px;
-    }
-    .band-controls {
-        display: flex;
-        flex-wrap: wrap;
-        gap: 8px;
-        align-items: center;
-    }
-    .band-row {
-        display: flex;
-        gap: 8px;
-        align-items: center;
-    }
-    .band-columns {
-        max-width: 720px;
-    }
-    .filter-row-cell {
-        display: flex;
-        align-items: center;
-        gap: 4px;
-        flex-wrap: wrap;
-    }
-    .filter-operator {
-        width: 52px;
-        min-width: 52px;
-        flex: 0 0 52px;
-    }
-    .filter-value {
-        min-width: 160px;
-        flex: 1 1 160px;
-    }
-    .loading-container {
-        min-height: 160px;
-        display: flex;
-        align-items: center;
-        justify-content: center;
-    }
-</style>
-
 @if (!string.IsNullOrWhiteSpace(errorMessage))
 {
     <div class="alert alert-danger" role="alert">@errorMessage</div>