refactor: replace Loader2 with Spinner component across the application

This update standardizes the loading indicators by replacing all instances of Loader2 with the new Spinner component. The Spinner component provides a consistent look and feel for loading states throughout the UI, enhancing the user experience.

Changes include:
- Updated loading indicators in various components such as popovers, modals, and views.
- Ensured that the Spinner component is used with appropriate sizes for different contexts.

No functional changes were made; this is purely a visual and structural improvement.

apps/ui/src/components/views/analysis-view.tsx

@@ -14,12 +14,12 @@ import {
   RefreshCw,
   BarChart3,
   FileCode,
-  Loader2,
   FileText,
   CheckCircle,
   AlertCircle,
   ListChecks,
 } from 'lucide-react';
+import { Spinner } from '@/components/ui/spinner';
 import { cn, generateUUID } from '@/lib/utils';
 
 const logger = createLogger('AnalysisView');
@@ -742,7 +742,7 @@ ${Object.entries(projectAnalysis.filesByExtension)
         <Button onClick={runAnalysis} disabled={isAnalyzing} data-testid="analyze-project-button">
           {isAnalyzing ? (
             <>
-              <Loader2 className="w-4 h-4 mr-2 animate-spin" />
+              <Spinner size="sm" className="mr-2" />
               Analyzing...
             </>
           ) : (
@@ -771,7 +771,7 @@ ${Object.entries(projectAnalysis.filesByExtension)
           </div>
         ) : isAnalyzing ? (
           <div className="flex flex-col items-center justify-center h-full">
-            <Loader2 className="w-12 h-12 animate-spin text-primary mb-4" />
+            <Spinner size="xl" className="mb-4" />
             <p className="text-muted-foreground">Scanning project files...</p>
           </div>
         ) : projectAnalysis ? (
@@ -850,7 +850,7 @@ ${Object.entries(projectAnalysis.filesByExtension)
                   >
                     {isGeneratingSpec ? (
                       <>
-                        <Loader2 className="w-4 h-4 mr-2 animate-spin" />
+                        <Spinner size="sm" className="mr-2" />
                         Generating...
                       </>
                     ) : (
@@ -903,7 +903,7 @@ ${Object.entries(projectAnalysis.filesByExtension)
                   >
                     {isGeneratingFeatureList ? (
                       <>
-                        <Loader2 className="w-4 h-4 mr-2 animate-spin" />
+                        <Spinner size="sm" className="mr-2" />
                         Generating...
                       </>
                     ) : (