feat: add config and credential storage

internal/config/config_test.go

@@ -0,0 +1,77 @@
+package config
+
+import (
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+)
+
+func TestLoadMissingConfigReturnsDefaults(t *testing.T) {
+	dir := t.TempDir()
+
+	cfg, err := Load(filepath.Join(dir, "config.json"))
+	if err != nil {
+		t.Fatalf("Load returned error: %v", err)
+	}
+
+	if cfg.Gitea.AuthType != "password" {
+		t.Fatalf("default auth type = %q, want password", cfg.Gitea.AuthType)
+	}
+	if !cfg.Update.AutoUpdate || !cfg.Update.CheckOnStartup {
+		t.Fatalf("update defaults should be enabled: %+v", cfg.Update)
+	}
+	if cfg.Update.IntervalMinutes != 60 {
+		t.Fatalf("interval = %d, want 60", cfg.Update.IntervalMinutes)
+	}
+}
+
+func TestSaveDoesNotPersistSecrets(t *testing.T) {
+	dir := t.TempDir()
+	path := filepath.Join(dir, "config.json")
+	cfg := Default()
+	cfg.Gitea.BaseURL = "https://gitea.example.com"
+	cfg.Gitea.Org = "skills"
+	cfg.Gitea.Username = "alice"
+	cfg.Gitea.CredentialKey = "sgg-ai-skill-manager:gitea"
+
+	if err := Save(path, cfg); err != nil {
+		t.Fatalf("Save returned error: %v", err)
+	}
+
+	raw, err := os.ReadFile(path)
+	if err != nil {
+		t.Fatalf("ReadFile returned error: %v", err)
+	}
+	text := string(raw)
+	if containsAny(text, []string{"password-secret", "token-secret"}) {
+		t.Fatalf("config persisted a secret: %s", text)
+	}
+}
+
+func TestValidateRejectsMissingConnectionFields(t *testing.T) {
+	cfg := Default()
+
+	if err := Validate(cfg); err == nil {
+		t.Fatal("Validate returned nil error for empty config")
+	}
+
+	cfg.Gitea.BaseURL = "https://gitea.example.com"
+	if err := Validate(cfg); err == nil {
+		t.Fatal("Validate returned nil error without org")
+	}
+
+	cfg.Gitea.Org = "skills"
+	if err := Validate(cfg); err != nil {
+		t.Fatalf("Validate returned error for valid config: %v", err)
+	}
+}
+
+func containsAny(text string, needles []string) bool {
+	for _, needle := range needles {
+		if needle != "" && strings.Contains(text, needle) {
+			return true
+		}
+	}
+	return false
+}