fix: 订阅恢复补缺集/单媒体手动整理入口/媒体库排序/网盘媒体分类迁移

- 订阅(问题1): selectPreparedSubscriptionCandidates 在本地已有部分集时不再
  无条件丢弃整季/全集包,单集候选不足时用全集包兜底;Restore 重置 total_episodes
  让下次 run 从权威元数据重算,避免被 feed 低估值锁死误判'无缺集'
- 单媒体整理(问题2): 后端已具备,新增 OrganizeMediaDialog 组件并在媒体详情页
  接入'整理入库'按钮(可选类型/二级分类/目标路径/转移方式/预览)
- 媒体库排序(问题3): ListByLibrariesFiltered 改多级排序 year/updated_at/
  created_at/id,id 作稳定 tie-breaker 消除云盘批量扫描同批时间戳的随机观感
- 网盘媒体消失(问题4): 云盘媒体 upsert 时允许 library_id 迁移到重新挂载的
  更精确分类库(本地媒体物理位置固定不迁移),修复一键挂载子目录后媒体消失

internal/service/subscription.go

@@ -143,6 +143,11 @@ func (s *SubscriptionService) Restore(ctx context.Context, id string) (*model.Su
 		Updates(map[string]any{
 			"enabled":        true,
 			"archive_reason": "",
+			// 重置为 0:此前可能被 feed 低估并锁死(updateSubscriptionTotalEpisodes
+			// 只增不减,resolveSubscriptionTotalEpisodes 见 >0 即不再回查元数据)。
+			// 归零后下次 run 会从 TMDb/豆瓣等权威源重算真实总集数,避免恢复后
+			// 因"误判已无缺集"而不再搜索资源。
+			"total_episodes": 0,
 		}).Error; err != nil {
 		return nil, err
 	}

internal/service/subscription_planner.go

@@ -157,8 +157,16 @@ func selectPreparedSubscriptionCandidates(candidates []siteSearchCandidate, sub
 		}
 		missingSet := missingEpisodeSet(local)
 		onlyMissing := make([]siteSearchCandidate, 0, len(candidates))
-		for _, candidate := range candidates {
+		var packFallback *siteSearchCandidate
+		for i := range candidates {
+			candidate := candidates[i]
 			if candidate.Episode <= 0 {
+				// 整季/全集包(无单集号)。剧集完结后站点常只挂全集包,
+				// 这里记下来作兜底:当单集候选不足以补齐缺失集时启用,
+				// 否则"补全缺失集"在站点只有全集包时永远匹配为空。
+				if candidate.Pack && packFallback == nil {
+					packFallback = &candidates[i]
+				}
 				continue
 			}
 			season := candidate.Season
@@ -175,7 +183,13 @@ func selectPreparedSubscriptionCandidates(candidates []siteSearchCandidate, sub
 			}
 			onlyMissing = append(onlyMissing, candidate)
 		}
-		return sortedEpisodeCandidates(onlyMissing)
+		selected := sortedEpisodeCandidates(onlyMissing)
+		if len(selected) == 0 && packFallback != nil {
+			// 没有可用的单集候选,但站点有整季/全集包 → 用包兜底补缺集。
+			// 代价是会重下已有集,但用户主动触发补全时这是可接受的。
+			return []siteSearchCandidate{*packFallback}
+		}
+		return selected
 	}
 
 	for _, candidate := range candidates {

internal/service/subscription_test.go

@@ -283,7 +283,9 @@ func TestSelectSiteSearchCandidatesSingleExistingEpisodeIsSkipped(t *testing.T)
 	}
 }
 
-func TestSelectSiteSearchCandidatesSinglePackIsSkippedWhenLibraryPartiallyExists(t *testing.T) {
+func TestSelectSiteSearchCandidatesFullPackUsedAsFallbackWhenLibraryPartiallyExists(t *testing.T) {
+	// 本地缺第 3 集,站点只有整季全集包(无单集种)。剧集完结后站点常只挂全集包,
+	// 此时必须用全集包兜底补缺集,否则"补全缺失集"永远匹配为空(用户报告的 bug)。
 	sub := &model.Subscription{Name: "间谍过家家 自动订阅", Filter: "间谍过家家", MediaType: "tv", TotalEpisodes: 3}
 	results := []SearchResult{
 		{Title: "间谍过家家 S01 Complete 1080p", DownloadURL: "https://pt/download/pack", Seeders: 100},
@@ -296,8 +298,11 @@ func TestSelectSiteSearchCandidatesSinglePackIsSkippedWhenLibraryPartiallyExists
 	}
 
 	got := selectSiteSearchCandidates(results, sub, map[string]struct{}{}, availability)
-	if len(got) != 0 {
-		t.Fatalf("selected %#v, want none because a full pack would redownload existing episodes", got)
+	if len(got) != 1 {
+		t.Fatalf("selected %#v, want the full pack as fallback to cover missing episode 3", got)
+	}
+	if got[0].Download != "https://pt/download/pack" {
+		t.Fatalf("selected %#v, want the Complete pack", got)
 	}
 }
 
@@ -845,6 +850,9 @@ func TestRestoreArchivedSubscriptionReturnsToActiveAndClearsSeenState(t *testing
 	if restored.ArchivedAt != nil || restored.ArchiveReason != "" || !restored.Enabled {
 		t.Fatalf("restored subscription not active: archived=%v reason=%q enabled=%v", restored.ArchivedAt, restored.ArchiveReason, restored.Enabled)
 	}
+	if restored.TotalEpisodes != 0 {
+		t.Fatalf("restored total_episodes = %d, want 0 so it gets recomputed from authoritative metadata", restored.TotalEpisodes)
+	}
 	active, err := repos.Subscription.List(t.Context())
 	if err != nil {
 		t.Fatal(err)