fix: Add CORS support for Codespaces and restore MantineProvider

Backend changes:
- Updated CORS middleware to use allow_origin_regex pattern
- Allows all *.app.github.dev origins (Codespaces)
- Maintains localhost support for local development

Frontend changes:
- Restored MantineProvider wrapper in App.tsx
- Fixes crashes in PolicyList and PolicyViolations components
- Both shadcn/ui and Mantine components now work together

This resolves:
- CORS policy blocking API calls from Codespace frontend
- React crashes when rendering pages with Mantine components

Author: TamTunnel

AIGovHub/backend/app/main.py

@@ -22,9 +22,11 @@ async def lifespan(app: FastAPI):
     lifespan=lifespan
 )
 
+import re
+
 app.add_middleware(
     CORSMiddleware,
-    allow_origins=["http://localhost:5173", "http://localhost:3000"],
+    allow_origin_regex=r"https://.*\.app\.github\.dev|http://localhost:.*",
     allow_credentials=True,
     allow_methods=["*"],
     allow_headers=["*"],

AIGovHub/frontend/src/App.tsx

@@ -1,4 +1,5 @@
 import { BrowserRouter, Routes, Route } from "react-router-dom";
+import { MantineProvider } from "@mantine/core";
 import { ModelList } from "./components/ModelList";
 import { ModelForm } from "./components/ModelForm";
 import { ModelDetail } from "./components/ModelDetail";
@@ -9,18 +10,20 @@ import { AppShell } from "./components/layout/AppShell";
 
 function App() {
   return (
-    <BrowserRouter>
-      <AppShell>
-        <Routes>
-          <Route path="/" element={<ModelList />} />
-          <Route path="/dashboard" element={<ComplianceDashboard />} />
-          <Route path="/policies" element={<PolicyList />} />
-          <Route path="/violations" element={<PolicyViolations />} />
-          <Route path="/new" element={<ModelForm />} />
-          <Route path="/models/:id" element={<ModelDetail />} />
-        </Routes>
-      </AppShell>
-    </BrowserRouter>
+    <MantineProvider>
+      <BrowserRouter>
+        <AppShell>
+          <Routes>
+            <Route path="/" element={<ModelList />} />
+            <Route path="/dashboard" element={<ComplianceDashboard />} />
+            <Route path="/policies" element={<PolicyList />} />
+            <Route path="/violations" element={<PolicyViolations />} />
+            <Route path="/new" element={<ModelForm />} />
+            <Route path="/models/:id" element={<ModelDetail />} />
+          </Routes>
+        </AppShell>
+      </BrowserRouter>
+    </MantineProvider>
   );
 }