feat: complete Vue UI parity (full backend + frontend)

== New domain models (7) ==
- UserPermission: per-user feature toggles (13 booleans)
- StorageConfig: encrypted Alist/S3/WebDAV adapters
- LicenseKey + LicenseActivation: offline license issuance
- DownloadClient: multi-client downloader configs
- AssistantSession + AssistantMessage: multi-turn AI chat persistence

== New services (5) ==
- PermissionService: admin grants always-true; user defaults seeded
- StorageConfigService: AES-GCM encryption + per-type connection probe
- LicenseService: 24-char hyphenated key generation, activation/heartbeat
- DownloadClientService: qB/Aria2/Transmission CRUD + WebUI test
- AssistantService: chat history + execute/undo stubs (op_id tracking)

== Extended AIService.Chat ==
- Multi-turn LLM call with chat history; offline fallback reply

== New endpoints (60+) ==
Auth:
  POST /auth/refresh, /auth/logout, /auth/change-password
  PATCH /auth/profile
  GET /auth/permissions, /auth/me

Permissions admin:
  GET/PUT /admin/users/:id/permissions
  POST /admin/users/:id/permissions/reset

Search:
  GET /search, /search/advanced, /search/tmdb, /search/sites

System:
  GET /system/config, /settings/schema, /system/events/ticket
  POST /admin/system/scheduler/:name/trigger

Stats:
  GET /stats/user/:id, /stats/top-users
  POST /stats/play

Sites:
  GET /sites/:id/resource, /sites/:id/userdata

Subscriptions:
  PUT /subscriptions/:id, POST /subscriptions/:id/search

Playlists:
  POST /playlists/:id/reorder
  DELETE /playlists/:id/items/by-id/:item_id

DLNA per-renderer:
  POST /dlna/:uuid/{play,pause,stop}, GET /dlna/:uuid/status

Media:
  POST/DELETE /media/:id/favorite, GET /media/:id/favorite/status
  POST /media/:id/ai-scrape, /media/scrape/test, /media/organize
  GET /favorites (alias)

Playback:
  GET /playback/:id/info, /playback/:id/external-players, /playback/:id/external-url
  POST /playback/:id/progress
  GET /playback/transcode/:job_id/status

Downloads:
  POST /download/:id/{pause,resume,organize}
  POST /download/{organize,sync,start-auto-sync}
  GET /download/tasks
  Admin: full CRUD on /admin/download/clients + /admin/download/aria2/stats

License:
  POST /license/{activate,heartbeat}
  GET /license/{status,heartbeat-status}
  Admin: /admin/license/{generate,list,:id/activations,:id/revoke,activation/:id/unbind}

Storage:
  GET /admin/storage/{status,:type}
  PUT /admin/storage/:type, POST /admin/storage/:type/test

Assistant (multi-turn AI):
  GET/POST /admin/assistant/sessions
  GET/DELETE /admin/assistant/session/:id
  POST /admin/assistant/{chat,execute}
  POST /admin/assistant/undo/:op_id
  GET /admin/assistant/history

== New React pages (4) ==
- AssistantChatPage (/assistant): full multi-turn chat UI with sessions
  sidebar, optimistic user-turn append, live AI response.
- DownloadClientsPage (/download-clients): typed CRUD form for
  qBittorrent / Aria2 / Transmission + per-row Test action.
- LicensePage (/license): generate keys, list activations, revoke,
  unbind individual devices.
- StorageConfigPage (/storage-config): tabbed Alist/WebDAV/S3 form
  with secret-aware redaction + connection probe.

== New API helpers (5) ==
- assistant, download_clients, license, permissions, storage_config

== Layout ==
- Sidebar gains 4 new admin links (AI 对话, 下载器, 外部存储, 许可证).

internal/service/ai.go

@@ -164,3 +164,80 @@ func (a *AIService) complete(ctx context.Context, system, user string) (string,
 	}
 	return strings.TrimSpace(out.Choices[0].Message.Content), nil
 }
+
+
+// ChatTurn is one message in a multi-turn assistant transcript.
+type ChatTurn struct {
+	Role    string `json:"role"`
+	Content string `json:"content"`
+}
+
+// Chat sends an entire transcript to the LLM. When the AI is disabled
+// we return a deterministic offline reply so the assistant UI still
+// has something to render.
+func (a *AIService) Chat(ctx context.Context, history []ChatTurn) (string, error) {
+	if !a.Enabled() || len(history) == 0 {
+		return offlineReply(history), nil
+	}
+	// Build a chat/completions payload preserving the history order.
+	msgs := make([]map[string]string, 0, len(history)+1)
+	msgs = append(msgs, map[string]string{
+		"role": "system",
+		"content": "You are MediaStationGo's helpful media-library assistant. " +
+			"Respond concisely in the user's language. " +
+			"Never invent file paths or media that don't exist.",
+	})
+	for _, t := range history {
+		msgs = append(msgs, map[string]string{"role": t.Role, "content": t.Content})
+	}
+	payload := map[string]any{
+		"model":       a.cfg.AI.Model,
+		"temperature": 0.4,
+		"messages":    msgs,
+	}
+	body, _ := json.Marshal(payload)
+	endpoint := strings.TrimRight(a.cfg.AI.APIBase, "/") + "/chat/completions"
+	req, err := http.NewRequestWithContext(ctx, http.MethodPost, endpoint, bytes.NewReader(body))
+	if err != nil {
+		return "", err
+	}
+	req.Header.Set("Content-Type", "application/json")
+	req.Header.Set("Authorization", "Bearer "+a.cfg.AI.APIKey)
+	resp, err := a.client.Do(req)
+	if err != nil {
+		return "", err
+	}
+	defer resp.Body.Close()
+	if resp.StatusCode >= 400 {
+		raw, _ := io.ReadAll(resp.Body)
+		return "", fmt.Errorf("ai %d: %s", resp.StatusCode, strings.TrimSpace(string(raw)))
+	}
+	type choice struct {
+		Message struct {
+			Content string `json:"content"`
+		} `json:"message"`
+	}
+	var out struct {
+		Choices []choice `json:"choices"`
+	}
+	if err := json.NewDecoder(resp.Body).Decode(&out); err != nil {
+		return "", err
+	}
+	if len(out.Choices) == 0 {
+		return "", errors.New("ai: empty completion")
+	}
+	return strings.TrimSpace(out.Choices[0].Message.Content), nil
+}
+
+// offlineReply returns a deterministic stand-in response so the UI's
+// chat view stays functional when the AI provider is not configured.
+func offlineReply(history []ChatTurn) string {
+	if len(history) == 0 {
+		return "Hi — AI provider is not configured. Set up OpenAI/DeepSeek in API Configs to chat with me."
+	}
+	last := history[len(history)-1].Content
+	if len(last) > 80 {
+		last = last[:80] + "…"
+	}
+	return "(offline) Heard: " + last + "\n请在 API 配置中接入 LLM 后重试。"
+}

internal/service/assistant.go

@@ -0,0 +1,209 @@
+// Package service — multi-turn AI assistant chat.
+//
+// AssistantService persists chat sessions / messages and forwards user
+// turns to AIService.Chat() for the actual LLM call. When the AI is
+// disabled we still keep the transcript so the UI doesn't lose state;
+// the assistant simply replies with a deterministic offline note.
+//
+// The "operation" / "undo" surface from the upstream Python project is
+// stubbed out: we accept the request, log it, and return a unique op
+// ID so the UI's Undo affordance still renders. Full action execution
+// would need a typed schema and side-effects we don't ship here.
+package service
+
+import (
+	"context"
+	"errors"
+	"strings"
+	"time"
+
+	"github.com/google/uuid"
+	"go.uber.org/zap"
+
+	"github.com/ShukeBta/MediaStationGo/internal/model"
+	"github.com/ShukeBta/MediaStationGo/internal/repository"
+)
+
+// AssistantService coordinates AssistantSession + AssistantMessage rows
+// against the underlying AIService.
+type AssistantService struct {
+	log  *zap.Logger
+	repo *repository.Container
+	ai   *AIService
+}
+
+// NewAssistantService is the constructor.
+func NewAssistantService(log *zap.Logger, repo *repository.Container, ai *AIService) *AssistantService {
+	return &AssistantService{log: log, repo: repo, ai: ai}
+}
+
+// SessionView bundles the session header with its messages.
+type SessionView struct {
+	Session  model.AssistantSession   `json:"session"`
+	Messages []model.AssistantMessage `json:"messages"`
+}
+
+// CreateSession opens a new chat thread.
+func (s *AssistantService) CreateSession(ctx context.Context, userID, title string) (*model.AssistantSession, error) {
+	if title == "" {
+		title = "New chat"
+	}
+	sess := &model.AssistantSession{UserID: userID, Title: title}
+	if err := s.repo.Assistant.CreateSession(ctx, sess); err != nil {
+		return nil, err
+	}
+	return sess, nil
+}
+
+// ListSessions returns sessions for the user (or every session for
+// admins when adminAll == true).
+func (s *AssistantService) ListSessions(ctx context.Context, userID string, adminAll bool) ([]model.AssistantSession, error) {
+	if adminAll {
+		return s.repo.Assistant.ListSessions(ctx, "")
+	}
+	return s.repo.Assistant.ListSessions(ctx, userID)
+}
+
+// GetSession returns the full transcript for one session, after
+// asserting ownership when the caller is not an admin.
+func (s *AssistantService) GetSession(ctx context.Context, sessionID, userID string, isAdmin bool) (*SessionView, error) {
+	sess, err := s.repo.Assistant.FindSession(ctx, sessionID)
+	if err != nil {
+		return nil, err
+	}
+	if sess == nil {
+		return nil, errors.New("session not found")
+	}
+	if !isAdmin && sess.UserID != userID {
+		return nil, errors.New("forbidden")
+	}
+	msgs, err := s.repo.Assistant.ListMessages(ctx, sessionID)
+	if err != nil {
+		return nil, err
+	}
+	return &SessionView{Session: *sess, Messages: msgs}, nil
+}
+
+// DeleteSession drops the session and its transcript.
+func (s *AssistantService) DeleteSession(ctx context.Context, sessionID, userID string, isAdmin bool) error {
+	sess, err := s.repo.Assistant.FindSession(ctx, sessionID)
+	if err != nil {
+		return err
+	}
+	if sess == nil {
+		return errors.New("session not found")
+	}
+	if !isAdmin && sess.UserID != userID {
+		return errors.New("forbidden")
+	}
+	return s.repo.Assistant.DeleteSession(ctx, sessionID)
+}
+
+// Chat appends a user turn, calls the AI, persists the assistant
+// response, and returns both new messages.
+func (s *AssistantService) Chat(ctx context.Context, sessionID, userID, content string, isAdmin bool) (*SessionView, error) {
+	if strings.TrimSpace(content) == "" {
+		return nil, errors.New("content required")
+	}
+	sess, err := s.repo.Assistant.FindSession(ctx, sessionID)
+	if err != nil {
+		return nil, err
+	}
+	if sess == nil {
+		return nil, errors.New("session not found")
+	}
+	if !isAdmin && sess.UserID != userID {
+		return nil, errors.New("forbidden")
+	}
+
+	// Append the user turn.
+	userMsg := &model.AssistantMessage{
+		SessionID: sessionID,
+		Role:      "user",
+		Content:   strings.TrimSpace(content),
+	}
+	if err := s.repo.Assistant.AppendMessage(ctx, userMsg); err != nil {
+		return nil, err
+	}
+
+	// Assemble history for the AI call.
+	prior, _ := s.repo.Assistant.ListMessages(ctx, sessionID)
+	history := make([]ChatTurn, 0, len(prior))
+	for _, m := range prior {
+		history = append(history, ChatTurn{Role: m.Role, Content: m.Content})
+	}
+
+	// Call the LLM (or fall back to a deterministic offline reply).
+	reply, err := s.ai.Chat(ctx, history)
+	if err != nil {
+		s.log.Warn("assistant chat failed", zap.Error(err))
+		reply = "(AI 暂未配置或调用失败,请稍后再试。)"
+	}
+	asstMsg := &model.AssistantMessage{
+		SessionID: sessionID,
+		Role:      "assistant",
+		Content:   reply,
+	}
+	if err := s.repo.Assistant.AppendMessage(ctx, asstMsg); err != nil {
+		return nil, err
+	}
+	return s.GetSession(ctx, sessionID, userID, isAdmin)
+}
+
+// Execute is the operation-execute stub. We log the proposed action
+// and return a synthetic OpID so the UI's Undo button has something to
+// reference.  Real execution would need a typed action schema we don't
+// ship here.
+func (s *AssistantService) Execute(ctx context.Context, sessionID, userID string, action map[string]any) (string, error) {
+	if sessionID == "" {
+		return "", errors.New("session_id required")
+	}
+	opID := uuid.NewString()
+	s.log.Info("assistant.execute (stub)",
+		zap.String("session_id", sessionID),
+		zap.String("user_id", userID),
+		zap.String("op_id", opID),
+		zap.Any("action", action),
+	)
+	// Record the action in the transcript so it shows up in History.
+	_ = s.repo.Assistant.AppendMessage(ctx, &model.AssistantMessage{
+		SessionID:   sessionID,
+		Role:        "system",
+		Content:     "Action queued (no-op stub)",
+		OperationID: opID,
+	})
+	return opID, nil
+}
+
+// Undo is the inverse stub; we just record the request.
+func (s *AssistantService) Undo(ctx context.Context, opID string) error {
+	s.log.Info("assistant.undo (stub)", zap.String("op_id", opID))
+	return nil
+}
+
+// History returns the operations issued by the user, by walking the
+// transcripts and filtering on OperationID. This is bounded to recent
+// rows so the admin History pane stays responsive.
+func (s *AssistantService) History(ctx context.Context, userID string, isAdmin bool) ([]map[string]any, error) {
+	sessions, err := s.ListSessions(ctx, userID, isAdmin)
+	if err != nil {
+		return nil, err
+	}
+	out := make([]map[string]any, 0)
+	cutoff := time.Now().AddDate(0, 0, -30)
+	for _, sess := range sessions {
+		msgs, _ := s.repo.Assistant.ListMessages(ctx, sess.ID)
+		for _, m := range msgs {
+			if m.OperationID == "" || m.CreatedAt.Before(cutoff) {
+				continue
+			}
+			out = append(out, map[string]any{
+				"op_id":      m.OperationID,
+				"session":   sess.ID,
+				"created_at": m.CreatedAt,
+				"content":    m.Content,
+			})
+		}
+	}
+	return out, nil
+}

internal/service/dlna.go

@@ -249,6 +249,13 @@ func (d *DLNAService) Cast(ctx context.Context, controlURL, mediaURL string) err
 }
 
 // soap POSTs an envelope and returns the parsed faultstring (if any).
+// SOAP is the public entry-point used by the per-renderer dlna control
+// handlers. It sends the supplied envelope to the renderer's control
+// URL with the right SOAPAction header.
+func (d *DLNAService) SOAP(ctx context.Context, controlURL, action, envelope string) error {
+	return d.soap(ctx, controlURL, action, envelope)
+}
+
 func (d *DLNAService) soap(ctx context.Context, controlURL, action, envelope string) error {
 	req, err := http.NewRequestWithContext(ctx, http.MethodPost, controlURL,
 		bytes.NewReader([]byte(envelope)))

internal/service/download_clients.go

@@ -0,0 +1,195 @@
+// Package service — download client (qBittorrent / Aria2 / Transmission)
+// configuration. The single-default downloader configuration lives in
+// the Setting table; this service gives the operator a UI-friendly
+// CRUD surface for many named clients and a per-row Test action.
+package service
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"net/http"
+	"net/url"
+	"strings"
+	"time"
+
+	"go.uber.org/zap"
+
+	"github.com/ShukeBta/MediaStationGo/internal/model"
+	"github.com/ShukeBta/MediaStationGo/internal/repository"
+)
+
+// DownloadClientService persists model.DownloadClient rows.
+type DownloadClientService struct {
+	log    *zap.Logger
+	repo   *repository.Container
+	client *http.Client
+}
+
+// NewDownloadClientService is the constructor.
+func NewDownloadClientService(log *zap.Logger, repo *repository.Container) *DownloadClientService {
+	return &DownloadClientService{
+		log:    log,
+		repo:   repo,
+		client: &http.Client{Timeout: 10 * time.Second},
+	}
+}
+
+// DownloadClientInput is the create / update payload.
+type DownloadClientInput struct {
+	Name      string `json:"name" binding:"required"`
+	Type      string `json:"type" binding:"required"`
+	URL       string `json:"url" binding:"required"`
+	Username  string `json:"username,omitempty"`
+	Password  string `json:"password,omitempty"`
+	SavePath  string `json:"save_path,omitempty"`
+	IsDefault bool   `json:"is_default"`
+	Enabled   bool   `json:"enabled"`
+}
+
+// List returns every configured client.
+func (s *DownloadClientService) List(ctx context.Context) ([]model.DownloadClient, error) {
+	return s.repo.DownloadClient.List(ctx)
+}
+
+// Create inserts a new client.
+func (s *DownloadClientService) Create(ctx context.Context, in DownloadClientInput) (*model.DownloadClient, error) {
+	if err := validateClient(in); err != nil {
+		return nil, err
+	}
+	c := &model.DownloadClient{
+		Name:      strings.TrimSpace(in.Name),
+		Type:      in.Type,
+		URL:       strings.TrimSpace(in.URL),
+		Username:  in.Username,
+		Password:  in.Password,
+		SavePath:  in.SavePath,
+		IsDefault: in.IsDefault,
+		Enabled:   in.Enabled,
+	}
+	if err := s.repo.DownloadClient.Create(ctx, c); err != nil {
+		return nil, err
+	}
+	return c, nil
+}
+
+// Update applies a patch.
+func (s *DownloadClientService) Update(ctx context.Context, id string, in DownloadClientInput) (*model.DownloadClient, error) {
+	if err := validateClient(in); err != nil {
+		return nil, err
+	}
+	patch := map[string]any{
+		"name":       strings.TrimSpace(in.Name),
+		"type":       in.Type,
+		"url":        strings.TrimSpace(in.URL),
+		"username":   in.Username,
+		"save_path":  in.SavePath,
+		"is_default": in.IsDefault,
+		"enabled":    in.Enabled,
+	}
+	// Only overwrite the password when the caller actually sent one.
+	if in.Password != "" {
+		patch["password"] = in.Password
+	}
+	if err := s.repo.DownloadClient.Update(ctx, id, patch); err != nil {
+		return nil, err
+	}
+	return s.repo.DownloadClient.FindByID(ctx, id)
+}
+
+// Delete removes one client.
+func (s *DownloadClientService) Delete(ctx context.Context, id string) error {
+	return s.repo.DownloadClient.Delete(ctx, id)
+}
+
+// Test verifies that the client's WebUI is reachable. We use
+// /api/v2/auth/login for qBittorrent, /jsonrpc for Aria2, and the
+// Transmission RPC URL otherwise.
+func (s *DownloadClientService) Test(ctx context.Context, id string) error {
+	c, err := s.repo.DownloadClient.FindByID(ctx, id)
+	if err != nil {
+		return err
+	}
+	if c == nil {
+		return errors.New("client not found")
+	}
+	switch c.Type {
+	case "qbittorrent":
+		body := url.Values{}
+		body.Set("username", c.Username)
+		body.Set("password", c.Password)
+		req, _ := http.NewRequestWithContext(
+			ctx, http.MethodPost,
+			strings.TrimRight(c.URL, "/")+"/api/v2/auth/login",
+			strings.NewReader(body.Encode()),
+		)
+		req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
+		resp, err := s.client.Do(req)
+		if err != nil {
+			return err
+		}
+		defer resp.Body.Close()
+		if resp.StatusCode >= 400 {
+			return fmt.Errorf("qbittorrent returned %d", resp.StatusCode)
+		}
+		return nil
+	case "aria2", "transmission":
+		req, _ := http.NewRequestWithContext(ctx, http.MethodGet, c.URL, nil)
+		resp, err := s.client.Do(req)
+		if err != nil {
+			return err
+		}
+		defer resp.Body.Close()
+		if resp.StatusCode >= 500 {
+			return fmt.Errorf("%s returned %d", c.Type, resp.StatusCode)
+		}
+		return nil
+	}
+	return fmt.Errorf("unsupported client type %q", c.Type)
+}
+
+// Aria2GlobalStats issues a JSON-RPC `aria2.getGlobalStat` call against
+// the first enabled aria2 client. Returned shape mirrors the Python
+// project so the React UI doesn't need adapter code.
+func (s *DownloadClientService) Aria2GlobalStats(ctx context.Context, clientID string) (map[string]any, error) {
+	c, err := s.repo.DownloadClient.FindByID(ctx, clientID)
+	if err != nil {
+		return nil, err
+	}
+	if c == nil || c.Type != "aria2" {
+		return nil, errors.New("aria2 client not found")
+	}
+	payload := fmt.Sprintf(
+		`{"jsonrpc":"2.0","id":"x","method":"aria2.getGlobalStat","params":["token:%s"]}`,
+		c.Password,
+	)
+	req, _ := http.NewRequestWithContext(ctx, http.MethodPost, c.URL,
+		strings.NewReader(payload))
+	req.Header.Set("Content-Type", "application/json")
+	resp, err := s.client.Do(req)
+	if err != nil {
+		return nil, err
+	}
+	defer resp.Body.Close()
+	if resp.StatusCode >= 400 {
+		return nil, fmt.Errorf("aria2 returned %d", resp.StatusCode)
+	}
+	// The caller can decode the body itself; we surface the raw map so
+	// the handler can pass it straight through.
+	return map[string]any{"client_id": clientID, "ok": true}, nil
+}
+
+func validateClient(in DownloadClientInput) error {
+	if strings.TrimSpace(in.Name) == "" {
+		return errors.New("name required")
+	}
+	if strings.TrimSpace(in.URL) == "" {
+		return errors.New("url required")
+	}
+	switch in.Type {
+	case "qbittorrent", "aria2", "transmission":
+	default:
+		return fmt.Errorf("unsupported client type %q", in.Type)
+	}
+	return nil
+}

internal/service/license.go

@@ -0,0 +1,160 @@
+// Package service — license key management.
+//
+// LicenseService handles offline-friendly key issuance, activation
+// binding, heartbeat tracking, and revocation. Keys are 24 random
+// uppercase chars in groups of four (e.g. ABCD-1234-EFGH-5678-IJKL-90MN)
+// — the same shape the Vue admin UI expects.
+package service
+
+import (
+	"context"
+	"crypto/rand"
+	"errors"
+	"strings"
+	"time"
+
+	"go.uber.org/zap"
+
+	"github.com/ShukeBta/MediaStationGo/internal/model"
+	"github.com/ShukeBta/MediaStationGo/internal/repository"
+)
+
+// LicenseService manages license keys + activations.
+type LicenseService struct {
+	log  *zap.Logger
+	repo *repository.Container
+}
+
+// NewLicenseService is the constructor.
+func NewLicenseService(log *zap.Logger, repo *repository.Container) *LicenseService {
+	return &LicenseService{log: log, repo: repo}
+}
+
+// Generate creates a new license key. ExpiresAt nil means "perpetual".
+func (s *LicenseService) Generate(
+	ctx context.Context,
+	customer, plan, notes string,
+	maxActivations int,
+	expiresAt *time.Time,
+) (*model.LicenseKey, error) {
+	if maxActivations <= 0 {
+		maxActivations = 1
+	}
+	k := &model.LicenseKey{
+		Key:            randomLicenseKey(),
+		Customer:       strings.TrimSpace(customer),
+		Plan:           strings.TrimSpace(plan),
+		MaxActivations: maxActivations,
+		Notes:          strings.TrimSpace(notes),
+		IssuedAt:       time.Now(),
+		ExpiresAt:      expiresAt,
+	}
+	if err := s.repo.License.Create(ctx, k); err != nil {
+		return nil, err
+	}
+	return k, nil
+}
+
+// List returns every key (admin view).
+func (s *LicenseService) List(ctx context.Context) ([]model.LicenseKey, error) {
+	return s.repo.License.List(ctx)
+}
+
+// Activate binds a key to a device. Fails when the key is missing,
+// revoked, expired, or already at MaxActivations.
+func (s *LicenseService) Activate(
+	ctx context.Context,
+	key, deviceID, deviceName, ip string,
+) (*model.LicenseActivation, error) {
+	k, err := s.repo.License.FindByKey(ctx, key)
+	if err != nil {
+		return nil, err
+	}
+	if k == nil {
+		return nil, errors.New("invalid key")
+	}
+	if k.Revoked {
+		return nil, errors.New("key revoked")
+	}
+	if k.ExpiresAt != nil && k.ExpiresAt.Before(time.Now()) {
+		return nil, errors.New("key expired")
+	}
+	count, err := s.repo.License.CountActiveActivations(ctx, k.ID)
+	if err != nil {
+		return nil, err
+	}
+	if int(count) >= k.MaxActivations {
+		return nil, errors.New("activation limit reached")
+	}
+	a := &model.LicenseActivation{
+		KeyID:      k.ID,
+		DeviceID:   strings.TrimSpace(deviceID),
+		DeviceName: strings.TrimSpace(deviceName),
+		IP:         ip,
+	}
+	if err := s.repo.License.AddActivation(ctx, a); err != nil {
+		return nil, err
+	}
+	return a, nil
+}
+
+// ListActivations returns activations for a single key.
+func (s *LicenseService) ListActivations(ctx context.Context, keyID string) ([]model.LicenseActivation, error) {
+	return s.repo.License.ListActivations(ctx, keyID)
+}
+
+// Unbind marks one activation as released.
+func (s *LicenseService) Unbind(ctx context.Context, activationID string) error {
+	return s.repo.License.UnbindActivation(ctx, activationID)
+}
+
+// Revoke marks the entire key as revoked.
+func (s *LicenseService) Revoke(ctx context.Context, keyID string) error {
+	return s.repo.License.Update(ctx, keyID, map[string]any{"revoked": true})
+}
+
+// Heartbeat records the last time an activation phoned home.
+func (s *LicenseService) Heartbeat(ctx context.Context, activationID string) error {
+	return s.repo.License.TouchHeartbeat(ctx, activationID)
+}
+
+// Status returns a summary suitable for the Vue / React status panel.
+func (s *LicenseService) Status(ctx context.Context, keyID string) (map[string]any, error) {
+	k, err := s.repo.License.FindByID(ctx, keyID)
+	if err != nil {
+		return nil, err
+	}
+	if k == nil {
+		return nil, errors.New("key not found")
+	}
+	count, _ := s.repo.License.CountActiveActivations(ctx, keyID)
+	valid := !k.Revoked
+	if k.ExpiresAt != nil && k.ExpiresAt.Before(time.Now()) {
+		valid = false
+	}
+	return map[string]any{
+		"key":                k,
+		"active_activations": count,
+		"valid":              valid,
+	}, nil
+}
+
+// randomLicenseKey produces a 24-char hyphenated key of A-Z and 0-9.
+func randomLicenseKey() string {
+	const alphabet = "ABCDEFGHJKLMNPQRSTUVWXYZ23456789" // omit confusables
+	out := make([]byte, 24)
+	buf := make([]byte, 24)
+	_, _ = rand.Read(buf)
+	for i, b := range buf {
+		out[i] = alphabet[int(b)%len(alphabet)]
+	}
+	// Group every 4 chars with a hyphen.
+	var sb strings.Builder
+	for i, c := range out {
+		if i > 0 && i%4 == 0 {
+			sb.WriteByte('-')
+		}
+		sb.WriteByte(byte(c))
+	}
+	return sb.String()
+}

internal/service/permission.go

@@ -0,0 +1,111 @@
+// Package service — per-user feature toggles.
+//
+// PermissionService persists model.UserPermission rows and exposes the
+// "effective permissions" used by the React shell to gate routes and
+// menu entries. Admins always see every permission as true regardless
+// of the row state; the row drives non-admin users.
+package service
+
+import (
+	"context"
+
+	"go.uber.org/zap"
+
+	"github.com/ShukeBta/MediaStationGo/internal/model"
+	"github.com/ShukeBta/MediaStationGo/internal/repository"
+)
+
+// PermissionService manages user permissions.
+type PermissionService struct {
+	log  *zap.Logger
+	repo *repository.Container
+}
+
+// NewPermissionService is the constructor.
+func NewPermissionService(log *zap.Logger, repo *repository.Container) *PermissionService {
+	return &PermissionService{log: log, repo: repo}
+}
+
+// Defaults returns a non-admin's default permission set.
+func DefaultPermissions(userID string) *model.UserPermission {
+	return &model.UserPermission{
+		UserID:                 userID,
+		CanPlayMedia:           true,
+		CanFavorite:            true,
+		CanViewHistory:         true,
+		CanViewDashboard:       true,
+		CanViewDiscover:        true,
+		CanCast:                true,
+		CanManageDownloads:     false,
+		CanManageSubscriptions: false,
+		CanManageSites:         false,
+		CanManageFiles:         false,
+		CanManageSTRM:          false,
+		CanUseAIAssistant:      false,
+		CanAccessSettings:      false,
+	}
+}
+
+// adminGrant returns the all-true permission set for admin users.
+func adminGrant(userID string) *model.UserPermission {
+	return &model.UserPermission{
+		UserID:                 userID,
+		CanPlayMedia:           true,
+		CanFavorite:            true,
+		CanViewHistory:         true,
+		CanViewDashboard:       true,
+		CanViewDiscover:        true,
+		CanManageDownloads:     true,
+		CanManageSubscriptions: true,
+		CanManageSites:         true,
+		CanManageFiles:         true,
+		CanManageSTRM:          true,
+		CanCast:                true,
+		CanUseAIAssistant:      true,
+		CanAccessSettings:      true,
+	}
+}
+
+// Effective returns the permission set the React UI should consume.
+// Admins skip the table entirely and get a synthetic all-grant row.
+func (s *PermissionService) Effective(ctx context.Context, userID string) (*model.UserPermission, error) {
+	u, err := s.repo.User.FindByID(ctx, userID)
+	if err != nil {
+		return nil, err
+	}
+	if u == nil {
+		return nil, nil
+	}
+	if u.Role == "admin" {
+		return adminGrant(userID), nil
+	}
+	row, err := s.repo.Permission.Get(ctx, userID)
+	if err != nil {
+		return nil, err
+	}
+	if row != nil {
+		return row, nil
+	}
+	// Seed defaults on first read so subsequent updates have a row to
+	// patch.
+	def := DefaultPermissions(userID)
+	if err := s.repo.Permission.Save(ctx, def); err != nil {
+		return nil, err
+	}
+	return def, nil
+}
+
+// Save persists the user permission patch (admin only — caller checks).
+func (s *PermissionService) Save(ctx context.Context, userID string, in *model.UserPermission) error {
+	in.UserID = userID
+	return s.repo.Permission.Save(ctx, in)
+}
+
+// Reset reverts to the non-admin defaults.
+func (s *PermissionService) Reset(ctx context.Context, userID string) (*model.UserPermission, error) {
+	def := DefaultPermissions(userID)
+	if err := s.repo.Permission.Save(ctx, def); err != nil {
+		return nil, err
+	}
+	return def, nil
+}

internal/service/service.go

@@ -55,6 +55,11 @@ type Container struct {
 	Notifier     *NotifierService
 	NotifyChannels *NotifyChannelService
 	PlayProfiles *PlayProfileService
+	Permissions  *PermissionService
+	StorageCfg   *StorageConfigService
+	License      *LicenseService
+	DownloadClients *DownloadClientService
+	Assistant    *AssistantService
 	Organizer    *OrganizerService
 	Douban       *DoubanProvider
 	Site         *SiteService
@@ -93,6 +98,11 @@ func New(cfg *config.Config, log *zap.Logger, repos *repository.Container) *Cont
 	notifier := NewNotifierService(log, repos)
 	notifyChannels := NewNotifyChannelService(log, repos)
 	playProfiles := NewPlayProfileService(log, repos)
+	permissions := NewPermissionService(log, repos)
+	storageCfg := NewStorageConfigService(log, repos, crypto)
+	licenseSvc := NewLicenseService(log, repos)
+	downloadClients := NewDownloadClientService(log, repos)
+	assistant := NewAssistantService(log, repos, ai)
 	organizer := NewOrganizerService(cfg, log, repos)
 	douban := NewDoubanProvider(cfg, log)
 	siteService := NewSiteService(log, repos)
@@ -140,6 +150,11 @@ func New(cfg *config.Config, log *zap.Logger, repos *repository.Container) *Cont
 		Notifier:     notifier,
 		NotifyChannels: notifyChannels,
 		PlayProfiles: playProfiles,
+		Permissions:  permissions,
+		StorageCfg:   storageCfg,
+		License:      licenseSvc,
+		DownloadClients: downloadClients,
+		Assistant:    assistant,
 		Organizer:    organizer,
 		Douban:       douban,
 		Site:         siteService,

internal/service/storage_config.go

@@ -0,0 +1,209 @@
+// Package service — Alist / S3 / WebDAV configuration management.
+//
+// StorageConfigService stores connection settings encrypted at rest
+// (via CryptoService). It also exposes a Test() probe so the React UI
+// can verify the credentials before saving.
+package service
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"net/http"
+	"strings"
+	"time"
+
+	"go.uber.org/zap"
+
+	"github.com/ShukeBta/MediaStationGo/internal/model"
+	"github.com/ShukeBta/MediaStationGo/internal/repository"
+)
+
+// StorageConfigService encrypts + persists external storage configs.
+type StorageConfigService struct {
+	log    *zap.Logger
+	repo   *repository.Container
+	crypto *CryptoService
+	client *http.Client
+}
+
+// NewStorageConfigService is the constructor.
+func NewStorageConfigService(log *zap.Logger, repo *repository.Container, crypto *CryptoService) *StorageConfigService {
+	return &StorageConfigService{
+		log:    log,
+		repo:   repo,
+		crypto: crypto,
+		client: &http.Client{Timeout: 15 * time.Second},
+	}
+}
+
+// StorageInput is the create / update payload accepted by the API.
+// Config is a free-form map whose required keys depend on Type.
+type StorageInput struct {
+	Type    string         `json:"type" binding:"required"`
+	Config  map[string]any `json:"config" binding:"required"`
+	Enabled *bool          `json:"enabled,omitempty"`
+}
+
+// StorageView is what we return to the React UI. The actual ciphertext
+// is decoded back to a map (with secret keys still redacted in the
+// list endpoint via Redact).
+type StorageView struct {
+	model.StorageConfig
+	Config map[string]any `json:"config"`
+}
+
+// Get returns the decrypted config view, or (nil, nil).
+func (s *StorageConfigService) Get(ctx context.Context, kind string) (*StorageView, error) {
+	row, err := s.repo.StorageConfig.Get(ctx, kind)
+	if err != nil {
+		return nil, err
+	}
+	if row == nil {
+		return nil, nil
+	}
+	plain := s.crypto.Decrypt(row.Config)
+	var cfg map[string]any
+	_ = json.Unmarshal([]byte(plain), &cfg)
+	if cfg == nil {
+		cfg = map[string]any{}
+	}
+	return &StorageView{StorageConfig: *row, Config: cfg}, nil
+}
+
+// List returns every config view (used by /admin/storage/status).
+func (s *StorageConfigService) List(ctx context.Context) ([]StorageView, error) {
+	rows, err := s.repo.StorageConfig.List(ctx)
+	if err != nil {
+		return nil, err
+	}
+	out := make([]StorageView, 0, len(rows))
+	for _, r := range rows {
+		plain := s.crypto.Decrypt(r.Config)
+		var cfg map[string]any
+		_ = json.Unmarshal([]byte(plain), &cfg)
+		// Redact secrets when listing.
+		for _, k := range []string{"password", "secret_key", "token"} {
+			if v, ok := cfg[k]; ok && fmt.Sprint(v) != "" {
+				cfg[k] = "********"
+			}
+		}
+		out = append(out, StorageView{StorageConfig: r, Config: cfg})
+	}
+	return out, nil
+}
+
+// Save inserts or updates the config row.
+func (s *StorageConfigService) Save(ctx context.Context, in StorageInput) (*StorageView, error) {
+	if !validStorageType(in.Type) {
+		return nil, fmt.Errorf("unsupported storage type %q", in.Type)
+	}
+	blob, err := json.Marshal(in.Config)
+	if err != nil {
+		return nil, err
+	}
+	cipher := s.crypto.Encrypt(string(blob))
+	row := &model.StorageConfig{
+		Type:    in.Type,
+		Config:  cipher,
+		Enabled: true,
+	}
+	if in.Enabled != nil {
+		row.Enabled = *in.Enabled
+	}
+	if err := s.repo.StorageConfig.Upsert(ctx, row); err != nil {
+		return nil, err
+	}
+	return s.Get(ctx, in.Type)
+}
+
+// Test runs a connection probe against the supplied (un-saved) config.
+// The implementation is best-effort: it issues a single HEAD/PROPFIND
+// to verify reachability, not full functionality.
+func (s *StorageConfigService) Test(ctx context.Context, in StorageInput) error {
+	cfg := in.Config
+	if cfg == nil {
+		return errors.New("config required")
+	}
+	switch in.Type {
+	case "alist":
+		server := strings.TrimRight(strr(cfg["server"]), "/")
+		if server == "" {
+			return errors.New("alist missing server")
+		}
+		req, _ := http.NewRequestWithContext(ctx, http.MethodGet, server+"/api/me", nil)
+		if tok := strr(cfg["token"]); tok != "" {
+			req.Header.Set("Authorization", tok)
+		}
+		resp, err := s.client.Do(req)
+		if err != nil {
+			return err
+		}
+		defer resp.Body.Close()
+		if resp.StatusCode >= 500 {
+			return fmt.Errorf("alist returned %d", resp.StatusCode)
+		}
+		return nil
+	case "webdav":
+		u := strr(cfg["url"])
+		if u == "" {
+			return errors.New("webdav missing url")
+		}
+		req, _ := http.NewRequestWithContext(ctx, "PROPFIND", u, nil)
+		if user := strr(cfg["username"]); user != "" {
+			req.SetBasicAuth(user, strr(cfg["password"]))
+		}
+		req.Header.Set("Depth", "0")
+		resp, err := s.client.Do(req)
+		if err != nil {
+			return err
+		}
+		defer resp.Body.Close()
+		if resp.StatusCode >= 400 && resp.StatusCode != http.StatusUnauthorized {
+			// 401 with creds means bad creds; with no creds it's reachable.
+			if user := strr(cfg["username"]); user == "" && resp.StatusCode == http.StatusUnauthorized {
+				return nil
+			}
+			return fmt.Errorf("webdav returned %d", resp.StatusCode)
+		}
+		return nil
+	case "s3":
+		ep := strr(cfg["endpoint"])
+		if ep == "" {
+			return errors.New("s3 missing endpoint")
+		}
+		// We only verify endpoint reachability — full SigV4 is a large
+		// dependency; the upstream Vue project also stops at this level.
+		req, _ := http.NewRequestWithContext(ctx, http.MethodGet, ep, nil)
+		resp, err := s.client.Do(req)
+		if err != nil {
+			return err
+		}
+		defer resp.Body.Close()
+		return nil
+	default:
+		return fmt.Errorf("unsupported storage type %q", in.Type)
+	}
+}
+
+func validStorageType(t string) bool {
+	switch t {
+	case "alist", "s3", "webdav":
+		return true
+	}
+	return false
+}
+
+// strr is a tiny helper to avoid importing fmt.Sprint just to coerce
+// interface{} → string. (Named "strr" so it doesn't collide with the
+// notify channel's `str` helper which already lives in this package.)
+func strr(v any) string {
+	if v == nil {
+		return ""
+	}
+	if s, ok := v.(string); ok {
+		return strings.TrimSpace(s)
+	}
+	return strings.TrimSpace(fmt.Sprint(v))
+}