fix: sécuriser shutdown, config par défaut et reconnexion socket

Co-authored-by: aider (openrouter/openai/gpt-5.3-codex) <aider@aider.chat>

internal/config/loader_test.go

@@ -2,6 +2,7 @@ package config
 
 import (
 	"os"
+	"path/filepath"
 	"strings"
 	"testing"
 
@@ -211,3 +212,51 @@ func TestToJSON(t *testing.T) {
 		t.Error("ToJSON() result doesn't contain 'eth0'")
 	}
 }
+
+func TestLoad_DefaultConfigFileAbsent_DoesNotFail(t *testing.T) {
+	t.Setenv("JA4SENTINEL_INTERFACE", "")
+	t.Setenv("JA4SENTINEL_PORTS", "")
+	t.Setenv("JA4SENTINEL_BPF_FILTER", "")
+	t.Setenv("JA4SENTINEL_FLOW_TIMEOUT", "")
+
+	tempDir := t.TempDir()
+	oldWD, err := os.Getwd()
+	if err != nil {
+		t.Fatalf("Getwd() error = %v", err)
+	}
+	defer func() {
+		_ = os.Chdir(oldWD)
+	}()
+
+	if err := os.Chdir(tempDir); err != nil {
+		t.Fatalf("Chdir() error = %v", err)
+	}
+
+	_ = os.Remove(filepath.Join(tempDir, "config.yml"))
+
+	loader := NewLoader("")
+	cfg, err := loader.Load()
+	if err != nil {
+		t.Fatalf("Load() error = %v", err)
+	}
+
+	if cfg.Core.Interface != api.DefaultInterface {
+		t.Errorf("Interface = %q, want %q", cfg.Core.Interface, api.DefaultInterface)
+	}
+	if len(cfg.Core.ListenPorts) == 0 || cfg.Core.ListenPorts[0] != api.DefaultPort {
+		t.Errorf("ListenPorts = %v, want first port %d", cfg.Core.ListenPorts, api.DefaultPort)
+	}
+}
+
+func TestLoad_ExplicitMissingConfig_Fails(t *testing.T) {
+	t.Setenv("JA4SENTINEL_INTERFACE", "")
+	t.Setenv("JA4SENTINEL_PORTS", "")
+	t.Setenv("JA4SENTINEL_BPF_FILTER", "")
+	t.Setenv("JA4SENTINEL_FLOW_TIMEOUT", "")
+
+	loader := NewLoader("/tmp/definitely-missing-ja4sentinel.yml")
+	_, err := loader.Load()
+	if err == nil {
+		t.Fatal("Load() should fail with explicit missing config path")
+	}
+}