feat: settings window polish, sync widget fix, dark form controls

- Fix: settings overlay uses on:click|self so sidebar clicks don't close it
- Fix: openSettings(section) supports opening at specific tab
- Fix: 'Настроить' opens Settings → Синхронизация instead of Общие
- Style: dark theme select with custom arrow, global :global() CSS
- Style: settings cards, section descriptions, button/layout polish
- Style: settings gear buttons (icon-button pattern, 32px, soft hover)
- Style: settings sidebar with disabled stubs, consistent icons
- i18n: add generalDesc, workspaceDesc, appearance, localization keys

internal/core/config/appconfig.go

@@ -0,0 +1,139 @@
+package config
+
+import (
+	"encoding/json"
+	"fmt"
+	"os"
+	"path/filepath"
+)
+
+const (
+	AppConfigVersion  = 1
+	ConfigDirName     = "verstak"
+	AppConfigFileName = "config.json"
+)
+
+// AppConfig is the global application config stored at ~/.config/verstak/config.json.
+type AppConfig struct {
+	Version           int            `json:"version"`
+	VaultPath         string         `json:"vault_path"`
+	Theme             string         `json:"theme"`
+	Language          string         `json:"language"`
+	EnabledTemplates  []string       `json:"enabled_templates"`
+	EnabledPlugins    []string       `json:"enabled_plugins"`
+	FirstRunCompleted bool           `json:"first_run_completed"`
+	Window            WindowConfig   `json:"window,omitempty"`
+	Vault             VaultAppConfig `json:"vault,omitempty"`
+}
+
+type WindowConfig struct {
+	Width  int `json:"width,omitempty"`
+	Height int `json:"height,omitempty"`
+}
+
+// VaultAppConfig holds per-vault settings in the global config.
+type VaultAppConfig struct {
+	VaultID   string       `json:"vault_id,omitempty"`
+	CreatedAt string       `json:"created_at,omitempty"`
+	Sync      SyncSettings `json:"sync,omitempty"`
+}
+
+// SyncSettings holds sync configuration for the current vault.
+type SyncSettings struct {
+	Enabled      bool   `json:"enabled"`
+	ServerURL    string `json:"server_url"`
+	DeviceID     string `json:"device_id"`
+	DeviceName   string `json:"device_name"`
+	SyncInterval int    `json:"sync_interval"`
+	LastStatus   string `json:"last_status"`
+	LastSyncAt   string `json:"last_sync_at"`
+	LastError    string `json:"last_error,omitempty"`
+}
+
+func DefaultAppConfig() *AppConfig {
+	return &AppConfig{
+		Version:          AppConfigVersion,
+		Theme:            "system",
+		Language:         "ru",
+		EnabledTemplates: []string{"folder", "project", "client", "document", "recipe"},
+		EnabledPlugins:   []string{},
+	}
+}
+
+// ConfigDir returns ~/.config/verstak (or platform equivalent).
+func ConfigDir() (string, error) {
+	cfgDir, err := os.UserConfigDir()
+	if err != nil {
+		return "", err
+	}
+	return filepath.Join(cfgDir, ConfigDirName), nil
+}
+
+// AppConfigPath returns the path to config.json.
+func AppConfigPath() (string, error) {
+	dir, err := ConfigDir()
+	if err != nil {
+		return "", err
+	}
+	return filepath.Join(dir, AppConfigFileName), nil
+}
+
+// EnsureConfigDir creates the config directory if it doesn't exist.
+func EnsureConfigDir() (string, error) {
+	dir, err := ConfigDir()
+	if err != nil {
+		return "", err
+	}
+	if err := os.MkdirAll(dir, 0o750); err != nil {
+		return "", err
+	}
+	return dir, nil
+}
+
+// LoadAppConfig reads the global config from disk. Returns nil if the file doesn't exist.
+func LoadAppConfig() (*AppConfig, error) {
+	path, err := AppConfigPath()
+	if err != nil {
+		return nil, err
+	}
+	data, err := os.ReadFile(path)
+	if err != nil {
+		if os.IsNotExist(err) {
+			return nil, nil
+		}
+		return nil, fmt.Errorf("read config: %w", err)
+	}
+	if len(data) == 0 {
+		return nil, nil
+	}
+	var cfg AppConfig
+	if err := json.Unmarshal(data, &cfg); err != nil {
+		return nil, fmt.Errorf("parse config: %w", err)
+	}
+	return &cfg, nil
+}
+
+// SaveAppConfig writes the global config to disk.
+func SaveAppConfig(cfg *AppConfig) error {
+	path, err := AppConfigPath()
+	if err != nil {
+		return err
+	}
+	if _, err := EnsureConfigDir(); err != nil {
+		return err
+	}
+	data, err := json.MarshalIndent(cfg, "", "  ")
+	if err != nil {
+		return err
+	}
+	return os.WriteFile(path, data, 0o640)
+}
+
+// DefaultVaultPath returns the default vault location.
+func DefaultVaultPath() (string, error) {
+	dir, err := ConfigDir()
+	if err != nil {
+		return "", err
+	}
+	return filepath.Join(dir, "vault"), nil
+}