feat(frontend): Finalize auth refactor, routing, and resolve all code review findings

frontend/src/components/auth/RegisterForm.tsx

@@ -14,6 +14,7 @@ import {
 import { Input } from "@/components/ui/input"
 import { Card, CardContent, CardDescription, CardHeader, CardTitle } from "@/components/ui/card"
 import { useState } from "react"
+import axios from "axios"
 
 interface RegisterFormProps {
   onSuccess: () => void
@@ -38,12 +39,14 @@ export function RegisterForm({ onSuccess, onToggleMode }: RegisterFormProps) {
     setError(null)
     try {
       await AuthService.register(values.email, values.password)
-      // Automatically login after registration or just switch to login?
-      // For now, let's just switch to login or notify success
-      alert("Registration successful! Please login.")
-      onToggleMode()
-    } catch (err: any) {
-      setError(err.response?.data?.detail || "Registration failed. Please try again.")
+      // Since backend sets cookie on registration now, we can just call onSuccess
+      onSuccess()
+    } catch (err: unknown) {
+      if (axios.isAxiosError(err)) {
+        setError(err.response?.data?.detail || "Registration failed. Please try again.")
+      } else {
+        setError("An unexpected error occurred.")
+      }
     } finally {
       setIsLoading(false)
     }