perf(strm): 优化 OpenList 元数据下载速度 (#15)

* Add favourite buttons to library list and series detail pages

Co-authored-by: truewhile <truewhile@users.noreply.github.com>

* Fix favourites list for remote Emby mounted media

Co-authored-by: truewhile <truewhile@users.noreply.github.com>

* Route favourites to library series detail when appropriate

Co-authored-by: truewhile <truewhile@users.noreply.github.com>

* Fix favourites link to library series for remote anime paths

Co-authored-by: truewhile <truewhile@users.noreply.github.com>

* Fix remote Emby playback history and continue watching

- Preserve duration_ms when web player reports duration=0
- Add GET /playback/:id/resume for reliable per-item resume
- Switch home continue watching to /watch-history/continue API
- Set library_id on remote media for play-profile visibility
- Keep continue-watching rows when remote metadata hydration fails

Co-authored-by: truewhile <truewhile@users.noreply.github.com>

* Fix mobile sort dropdown overflowing off-screen

Align dropdown to button left edge on small screens and cap width
to viewport so sort options stay fully visible on mobile.

Co-authored-by: truewhile <truewhile@users.noreply.github.com>

* Remove stale Windows binary backup files

Co-authored-by: truewhile <truewhile@users.noreply.github.com>

* Fix STRM account edit form not echoing saved config

Return config_preview from account API for server/url/username and
secret flags. Merge partial config updates so empty password/token
fields do not wipe stored credentials.

Co-authored-by: truewhile <truewhile@users.noreply.github.com>

* perf(strm): speed up OpenList metadata downloads with provider-aware concurrency

- Split download semaphore: 115 stays capped at 3 for WAF safety; OpenList/CloudDrive2
  WebDAV metadata uses strm.download_threads (default raised to 6, max 16)
- Scope 115 WAF cooldown to 115 tasks only so OpenList downloads are not paused
- Requeue claimed tasks back to pending when slot acquisition fails or 115 is cooling
- Add tests for separate semaphores and requeue behavior

Co-authored-by: truewhile <truewhile@users.noreply.github.com>

---------

Co-authored-by: Cursor Agent <cursoragent@cursor.com>
Co-authored-by: truewhile <truewhile@users.noreply.github.com>

internal/service/strm_account_test.go

@@ -0,0 +1,76 @@
+package service
+
+import (
+	"context"
+	"encoding/json"
+	"testing"
+
+	"github.com/ShukeBta/MMTL/internal/model"
+)
+
+func TestStrmAccountConfigPreviewOf(t *testing.T) {
+	svc := testStrmService(t)
+	acct := &model.StrmAccount{
+		Provider: model.StrmProviderOpenList,
+		Config: mustJSON(map[string]string{
+			"server":   "https://list.example.com",
+			"username": "alice",
+			"password": svc.crypto.Encrypt("secret"),
+			"token":    svc.crypto.Encrypt("tok"),
+		}),
+	}
+
+	preview := svc.StrmAccountConfigPreviewOf(acct)
+	if preview.Server != "https://list.example.com" {
+		t.Fatalf("server = %q", preview.Server)
+	}
+	if preview.Username != "alice" {
+		t.Fatalf("username = %q", preview.Username)
+	}
+	if !preview.HasPassword || !preview.HasToken {
+		t.Fatalf("expected secret flags, got %#v", preview)
+	}
+}
+
+func TestUpdateStrmAccountMergesConfigWithoutClearingSecrets(t *testing.T) {
+	svc := testStrmService(t)
+	ctx := context.Background()
+	acct, err := svc.CreateStrmAccount(ctx, "openlist", model.StrmProviderOpenList, map[string]string{
+		"server":   "https://list.example.com",
+		"username": "alice",
+		"password": "secret",
+		"token":    "tok",
+	})
+	if err != nil {
+		t.Fatalf("create account: %v", err)
+	}
+
+	updated, err := svc.UpdateStrmAccount(ctx, acct.ID, "openlist-renamed", nil, map[string]string{
+		"server":   "https://list.example.com",
+		"username": "alice",
+	})
+	if err != nil {
+		t.Fatalf("update account: %v", err)
+	}
+	if updated.Name != "openlist-renamed" {
+		t.Fatalf("name = %q", updated.Name)
+	}
+	cfg, err := svc.strmAccountConfig(updated)
+	if err != nil {
+		t.Fatalf("decode config: %v", err)
+	}
+	if cfg["password"] != "secret" {
+		t.Fatalf("password was cleared: %#v", cfg)
+	}
+	if cfg["token"] != "tok" {
+		t.Fatalf("token was cleared: %#v", cfg)
+	}
+}
+
+func mustJSON(v any) string {
+	data, err := json.Marshal(v)
+	if err != nil {
+		panic(err)
+	}
+	return string(data)
+}