fix: improve OAuth button state handling and accessibility

- Move setOauthLoading(null) to finally block in both forms
  Ensures loading state is always reset, even if OAuth redirects or errors

- Add aria-label for screen readers when OAuth buttons show spinner
  Buttons now have 'Signing in with GitHub/Google' accessible name during loading

- Add sr-only span with provider name alongside Loader2 spinner
  Provides accessible text for assistive technologies

Author: DevanshuNEU

frontend/src/components/auth/LoginForm.tsx

@@ -39,6 +39,7 @@ export function LoginForm() {
       await signInWithGitHub()
     } catch (err: any) {
       setError(err.message || 'GitHub sign in failed')
+    } finally {
       setOauthLoading(null)
     }
   }
@@ -50,6 +51,7 @@ export function LoginForm() {
       await signInWithGoogle()
     } catch (err: any) {
       setError(err.message || 'Google sign in failed')
+    } finally {
       setOauthLoading(null)
     }
   }
@@ -152,9 +154,13 @@ export function LoginForm() {
                 className="h-10"
                 onClick={handleGitHubSignIn}
                 disabled={loading || oauthLoading !== null}
+                aria-label={oauthLoading === 'github' ? 'Signing in with GitHub' : undefined}
               >
                 {oauthLoading === 'github' ? (
-                  <Loader2 className="w-4 h-4 animate-spin" />
+                  <>
+                    <Loader2 className="w-4 h-4 animate-spin" />
+                    <span className="sr-only">Signing in with GitHub</span>
+                  </>
                 ) : (
                   <>
                     <Github className="w-4 h-4 mr-2" />
@@ -168,9 +174,13 @@ export function LoginForm() {
                 className="h-10"
                 onClick={handleGoogleSignIn}
                 disabled={loading || oauthLoading !== null}
+                aria-label={oauthLoading === 'google' ? 'Signing in with Google' : undefined}
               >
                 {oauthLoading === 'google' ? (
-                  <Loader2 className="w-4 h-4 animate-spin" />
+                  <>
+                    <Loader2 className="w-4 h-4 animate-spin" />
+                    <span className="sr-only">Signing in with Google</span>
+                  </>
                 ) : (
                   <>
                     <svg className="w-4 h-4 mr-2" viewBox="0 0 24 24">

frontend/src/components/auth/SignupForm.tsx

@@ -50,6 +50,7 @@ export function SignupForm() {
       await signInWithGitHub()
     } catch (err: any) {
       setError(err.message || 'GitHub sign in failed')
+    } finally {
       setOauthLoading(null)
     }
   }
@@ -61,6 +62,7 @@ export function SignupForm() {
       await signInWithGoogle()
     } catch (err: any) {
       setError(err.message || 'Google sign in failed')
+    } finally {
       setOauthLoading(null)
     }
   }
@@ -180,9 +182,13 @@ export function SignupForm() {
                 className="h-10"
                 onClick={handleGitHubSignIn}
                 disabled={loading || oauthLoading !== null}
+                aria-label={oauthLoading === 'github' ? 'Signing in with GitHub' : undefined}
               >
                 {oauthLoading === 'github' ? (
-                  <Loader2 className="w-4 h-4 animate-spin" />
+                  <>
+                    <Loader2 className="w-4 h-4 animate-spin" />
+                    <span className="sr-only">Signing in with GitHub</span>
+                  </>
                 ) : (
                   <>
                     <Github className="w-4 h-4 mr-2" />
@@ -196,9 +202,13 @@ export function SignupForm() {
                 className="h-10"
                 onClick={handleGoogleSignIn}
                 disabled={loading || oauthLoading !== null}
+                aria-label={oauthLoading === 'google' ? 'Signing in with Google' : undefined}
               >
                 {oauthLoading === 'google' ? (
-                  <Loader2 className="w-4 h-4 animate-spin" />
+                  <>
+                    <Loader2 className="w-4 h-4 animate-spin" />
+                    <span className="sr-only">Signing in with Google</span>
+                  </>
                 ) : (
                   <>
                     <svg className="w-4 h-4 mr-2" viewBox="0 0 24 24">