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+# Milestone 4 — App Settings + Vault Plugin State
+
+## Что реализовано
+
+### App Settings Core
+- Пакет `internal/core/appsettings/`
+- Хранение: `~/.config/verstak/config.json`
+- API: Load, Save, Update, SetCurrentVault, ClearCurrentVault
+- Поля: currentVaultPath, recentVaults, theme, devMode, userPluginsDir, windowState
+- Auto-open vault при запуске если currentVaultPath валиден
+- Corrupt config → backup + defaults с понятной ошибкой
+
+### Vault Plugin State
+- Пакет `internal/core/pluginstate/`
+- Хранение: `<vault>/.verstak/plugins.json`
+- API: Load, Save, EnablePlugin, DisablePlugin, IsEnabled, IsDisabled, RecordDesiredPlugin, ListMissingInstalled
+- Disabled plugin не регистрирует provides/contributions
+- Desired plugins для будущей синхронизации
+- Missing installed plugins tracking
+
+### Wails API
+- GetAppSettings, UpdateAppSettings
+- GetVaultPluginState, EnablePlugin, DisablePlugin
+
+### Lifecycle Integration
+- main.go: init app settings → auto-open vault → init plugin state → plugin discovery
+- Disabled plugins пропускаются в lifecycle (не регистрируют capabilities/contributions)
+- ReloadPlugins: проверка disabled state
+
+## Тесты
+
+### App Settings (6 тестов)
+- TestLoad_DefaultCreation
+- TestLoad_CorruptConfig
+- TestSetCurrentVault
+- TestRecentVaults_NoDuplicates
+- TestUpdate_Patch
+- TestAppSettings_NotInsideVault
+
+### Plugin State (7 тестов)
+- TestLoad_DefaultCreation
+- TestEnableDisable
+- TestDisablePlugin_Persists
+- TestRecordDesiredPlugin
+- TestMissingInstalled
+- TestCorruptPluginsJSON
+- TestVaultClosed_StateUnavailable
+
+## Верификация
+
+| command | result | notes |
+|---------|--------|-------|
+| `go test ./...` | ✅ | 52 PASS (39 prev + 6 appsettings + 7 pluginstate) |
+| `./scripts/check.sh` | ✅ | go vet + gofmt + go mod tidy OK |
+| `./scripts/build.sh` | ✅ | wails build OK |
+
+## Структура файлов
+
+```
+~/.config/verstak/
+  config.json          — app settings (local, NOT in vault)
+
+<vault>/
+  .verstak/
+    vault.json         — vault metadata
+    plugins.json       — vault plugin state
+    plugin-data/       — per-plugin data namespace
+    plugin-settings/   — per-plugin settings namespace
+    plugin-cache/      — per-plugin cache namespace
+```
+
+## Пример plugins.json
+
+```json
+{
+  "schemaVersion": 1,
+  "enabledPlugins": ["verstak.platform-test"],
+  "disabledPlugins": [],
+  "desiredPlugins": [
+    {
+      "id": "verstak.platform-test",
+      "version": "0.1.0",
+      "source": "official"
+    }
+  ],
+  "updatedAt": "2026-06-17T..."
+}
+```
+
+## Статус platform-test
+- DEGRADED — только из-за missing optional `verstak/core/sync/v1`
+- Enable/disable работает через vault plugin state
+- При disabled: provides не регистрируются, contributions не показываются
+- При enabled: всё возвращается
+
+## Что НЕ сделано
+- Notes/files/editor/sync
+- Auto-install plugins
+- First Run / Vault Selection UI (только backend, UI не готов)
+- Plugin Manager enable/disable toggle (только backend API)