feat: 实现智能分类功能

- 配置模型扩展（OrganizerConfig：smart_classify + categories）
- 数据模型扩展（Media：languages/countries/genres 字段）
- TMDbProvider 增强（GetDetails 方法获取扩展元数据）
- Scraper 服务增强（保存 languages/countries/genres 到数据库）
- Organizer 智能分类逻辑（根据元数据自动分类到子目录）
- 前端 SettingsPage 添加智能分类开关
- 后端支持从数据库读取 organizer.smart_classify 设置

Task #90-94 完成，Task #95 部分完成

internal/service/tmdb.go

@@ -80,14 +80,22 @@ func (t *TMDbProvider) Enabled() bool {
 func (t *TMDbProvider) resolveAPIKey(ctx context.Context) string {
 	// Check config first (fast path)
 	if t.cfg.Secrets.TMDbAPIKey != "" {
+		t.log.Debug("tmdb: using API key from config file")
 		return t.cfg.Secrets.TMDbAPIKey
 	}
 	// Fall back to database
 	if t.apiConfig != nil {
 		resolved, err := t.apiConfig.Resolve(ctx, "tmdb")
-		if err == nil && resolved.APIKey != "" {
+		if err != nil {
+			t.log.Warn("tmdb: failed to resolve API key from database", zap.Error(err))
+		} else if resolved.APIKey == "" {
+			t.log.Warn("tmdb: API key is empty in database")
+		} else {
+			t.log.Debug("tmdb: using API key from database")
 			return resolved.APIKey
 		}
+	} else {
+		t.log.Warn("tmdb: apiConfig is nil, cannot resolve API key from database")
 	}
 	return ""
 }
@@ -113,14 +121,17 @@ func (t *TMDbProvider) resolveBaseURL(ctx context.Context) string {
 // across providers; provider-specific IDs sit side-by-side so the scraper
 // orchestrator can write them all into a single update.
 type Match struct {
-	TMDbID      int     `json:"tmdb_id"`
-	BangumiID   int     `json:"bangumi_id"`
-	Title       string  `json:"title"`
-	Overview    string  `json:"overview"`
-	PosterURL   string  `json:"poster_url"`
-	BackdropURL string  `json:"backdrop_url"`
-	Year        int     `json:"year"`
-	Rating      float32 `json:"rating"`
+	TMDbID      int       `json:"tmdb_id"`
+	BangumiID   int       `json:"bangumi_id"`
+	Title       string    `json:"title"`
+	Overview    string    `json:"overview"`
+	PosterURL   string    `json:"poster_url"`
+	BackdropURL string    `json:"backdrop_url"`
+	Year        int       `json:"year"`
+	Rating      float32   `json:"rating"`
+	Languages   []string  `json:"languages,omitempty"`
+	Countries   []string  `json:"countries,omitempty"`
+	Genres     []string  `json:"genres,omitempty"`
 }
 
 // SearchMovie issues `/search/movie` and returns the best match, or nil
@@ -201,3 +212,134 @@ func (t *TMDbProvider) getJSON(ctx context.Context, url string, out any) error {
 	}
 	return json.NewDecoder(resp.Body).Decode(out)
 }
+
+// TMDbDetails holds extended metadata from the /movie/{id} or /tv/{id} endpoints.
+type TMDbDetails struct {
+	Languages []string `json:"languages"`
+	Countries []string `json:"countries"`
+	Genres    []string `json:"genres"`
+}
+
+// GetDetails fetches extended metadata for a TMDb ID.
+// It calls /movie/{id} or /tv/{id} with append_to_response=genres
+// and extracts languages, production countries, and genres.
+// mediaType should be "movie" or "tv".
+func (t *TMDbProvider) GetDetails(ctx context.Context, tmdbID int, mediaType string) (*TMDbDetails, error) {
+	apiKey := t.resolveAPIKey(ctx)
+	if apiKey == "" {
+		return nil, fmt.Errorf("tmdb: no API key available")
+	}
+	base := t.resolveBaseURL(ctx)
+
+	path := "/movie/" + fmt.Sprint(tmdbID)
+	if mediaType == "tv" {
+		path = "/tv/" + fmt.Sprint(tmdbID)
+	}
+
+	q := url.Values{}
+	q.Set("api_key", apiKey)
+	q.Set("language", "zh-CN")
+	q.Set("append_to_response", "genres")
+	u := base + path + "?" + q.Encode()
+
+	// Response structs for /movie/{id} and /tv/{id}
+	type genre struct {
+		Name string `json:"name"`
+	}
+	type movieResult struct {
+		OriginalLanguage  string   `json:"original_language"`
+		ProductionCountries []struct {
+			Iso3166_1 string `json:"iso_3166_1"`
+		} `json:"production_countries"`
+		SpokenLanguages []struct {
+			Iso639_1 string `json:"iso_639_1"`
+		} `json:"spoken_languages"`
+		Genres []genre `json:"genres"`
+	}
+	type tvResult struct {
+		OriginCountry []string `json:"origin_country"`
+		SpokenLanguages []struct {
+			Iso639_1 string `json:"iso_639_1"`
+		} `json:"spoken_languages"`
+		Genres []genre `json:"genres"`
+	}
+
+	var (
+		languages []string
+		countries []string
+		genres    []string
+	)
+
+	if mediaType == "tv" {
+		var r tvResult
+		if err := t.getJSON(ctx, u, &r); err != nil {
+			return nil, err
+		}
+		// Spoken languages
+		for _, l := range r.SpokenLanguages {
+			languages = append(languages, l.Iso639_1)
+		}
+		// Origin countries
+		countries = append(countries, r.OriginCountry...)
+		// Genres
+		for _, g := range r.Genres {
+			genres = append(genres, g.Name)
+		}
+	} else {
+		var r movieResult
+		if err := t.getJSON(ctx, u, &r); err != nil {
+			return nil, err
+		}
+		// Original language
+		if r.OriginalLanguage != "" {
+			languages = append(languages, r.OriginalLanguage)
+		}
+		// Spoken languages
+		for _, l := range r.SpokenLanguages {
+			languages = append(languages, l.Iso639_1)
+		}
+		// Production countries
+		for _, c := range r.ProductionCountries {
+			countries = append(countries, c.Iso3166_1)
+		}
+		// Genres
+		for _, g := range r.Genres {
+			genres = append(genres, g.Name)
+		}
+	}
+
+	// Deduplicate
+	languages = deduplicate(languages)
+	countries = deduplicate(countries)
+	genres = deduplicate(genres)
+
+	t.log.Debug("tmdb: getDetails",
+		zap.Int("tmdb_id", tmdbID),
+		zap.String("type", mediaType),
+		zap.Strings("languages", languages),
+		zap.Strings("countries", countries),
+		zap.Strings("genres", genres),
+	)
+
+	return &TMDbDetails{
+		Languages: languages,
+		Countries: countries,
+		Genres:    genres,
+	}, nil
+}
+
+// deduplicate removes duplicates from a string slice.
+func deduplicate(s []string) []string {
+	if len(s) == 0 {
+		return s
+	}
+	seen := make(map[string]bool, len(s))
+	out := make([]string, 0, len(s))
+	for _, v := range s {
+		if !seen[v] {
+			seen[v] = true
+			out = append(out, v)
+		}
+	}
+	return out
+}