test: Add example configuration and tests for endpoint-level auth

**Configuration:**
- Update config.yaml with endpoint-level auth example
- Add basic auth credentials and public endpoint markers
- Configure SQLite storage for testing

**Tests:**
- Add test for default auth level (global)
- Add test for invalid auth level validation
- Fix config test formatting

This demonstrates the endpoint-level authentication feature
where authentication is optional but filters visible data.

Author: loispostula

config/config_test.go

@@ -57,6 +57,7 @@ import (
 	"github.com/TwiN/gatus/v5/config/tunneling"
 	"github.com/TwiN/gatus/v5/config/tunneling/sshtunnel"
 	"github.com/TwiN/gatus/v5/config/web"
+	"github.com/TwiN/gatus/v5/security"
 	"github.com/TwiN/gatus/v5/storage"
 	"gopkg.in/yaml.v3"
 )
@@ -1864,8 +1865,8 @@ endpoints:
 	}
 	if config.Security.Basic.PasswordBcryptHashBase64Encoded != expectedPasswordHash {
 		t.Errorf("config.Security.Basic.PasswordBcryptHashBase64Encoded should've been %s, but was %s", expectedPasswordHash, config.Security.Basic.PasswordBcryptHashBase64Encoded)
-	}
-}
+	}}
+
 
 func TestParseAndValidateConfigBytesWithLiteralDollarSign(t *testing.T) {
 	os.Setenv("GATUS_TestParseAndValidateConfigBytesWithLiteralDollarSign", "whatever")

security/config_test.go

@@ -17,6 +17,21 @@ func TestConfig_ValidateAndSetDefaults(t *testing.T) {
 	if c.ValidateAndSetDefaults() {
 		t.Error("expected empty config to be valid")
 	}
+	if c.Level != authLevelGlobal {
+		t.Errorf("Default level should be %s", authLevelGlobal)
+	}
+}
+
+func TestConfig_ValidateLevel(t *testing.T) {
+	c := &Config{
+		Basic: nil,
+		OIDC:  nil,
+		Level: "WrongLevel",
+	}
+	valid := c.ValidateAndSetDefaults();
+	if valid {
+		t.Error("expected invalid level to mark config has invalid")
+	}
 }
 
 func TestConfig_ApplySecurityMiddleware(t *testing.T) {