feat: add migrate command, media server detection, and debrid auto-config

- Migration wizard from Sonarr/Radarr/Prowlarr (unarr migrate) [pre-beta]
  - Auto-detect instances via Docker, config files, port scan, Prowlarr
  - Import wanted list (monitored+missing movies/series)
  - Import download history and blocklist to avoid re-downloading
  - Extract debrid tokens from *arr download clients
  - Quality profile mapping to preferred_quality config
  - DISTINCT ON PostgreSQL query for optimal torrent selection
  - JSON export with --dry-run --json (text to stderr, JSON to stdout)
- Media server detection (Plex/Jellyfin/Emby) in unarr init
  - Detects library paths and offers them as download directory options
- Debrid auto-configuration in unarr init
  - Scans *arr instances for debrid tokens
  - Validates and saves via API if user confirms
- New preferred_quality setting in config (2160p/1080p/720p)
- Library scan command (unarr scan) with ffprobe metadata extraction

internal/agent/client.go

@@ -153,6 +153,33 @@ func (c *Client) GetUsenetUsage(ctx context.Context) (*UsenetUsageResponse, erro
 	return &resp, nil
 }
 
+// ConfigureDebrid saves a debrid provider token for the user (used by unarr init/migrate).
+func (c *Client) ConfigureDebrid(ctx context.Context, req ConfigureDebridRequest) (*ConfigureDebridResponse, error) {
+	var resp ConfigureDebridResponse
+	if err := c.doPost(ctx, "/api/internal/agent/debrid-config", req, &resp); err != nil {
+		return nil, fmt.Errorf("configure debrid: %w", err)
+	}
+	return &resp, nil
+}
+
+// BatchDownload queues multiple items for download (used by unarr migrate).
+func (c *Client) BatchDownload(ctx context.Context, req BatchDownloadRequest) (*BatchDownloadResponse, error) {
+	var resp BatchDownloadResponse
+	if err := c.doPost(ctx, "/api/internal/agent/batch-download", req, &resp); err != nil {
+		return nil, fmt.Errorf("batch download: %w", err)
+	}
+	return &resp, nil
+}
+
+// SyncLibrary sends scanned library items to the server for matching and upgrade discovery.
+func (c *Client) SyncLibrary(ctx context.Context, req LibrarySyncRequest) (*LibrarySyncResponse, error) {
+	var resp LibrarySyncResponse
+	if err := c.doPost(ctx, "/api/internal/agent/library-sync", req, &resp); err != nil {
+		return nil, fmt.Errorf("library sync: %w", err)
+	}
+	return &resp, nil
+}
+
 // doPost sends a JSON POST request and decodes the response.
 func (c *Client) doPost(ctx context.Context, path string, body any, dst any) error {
 	jsonBody, err := json.Marshal(body)

internal/agent/types.go

@@ -68,6 +68,8 @@ type Task struct {
 	DirectFileName  string `json:"directFileName,omitempty"` // Original filename from direct URL
 	NzbID           string `json:"nzbId,omitempty"`          // Pre-resolved NZB ID from server
 	NzbPassword     string `json:"nzbPassword,omitempty"`    // Password for encrypted NZB archives
+	ReplacePath     string `json:"replacePath,omitempty"`    // File to replace after download (upgrade mode)
+	LibraryItemID   int    `json:"libraryItemId,omitempty"`  // Library item being upgraded
 }
 
 // TasksResponse wraps the array of tasks returned by the server.
@@ -197,3 +199,102 @@ type UsenetUsageResponse struct {
 	RemainingBytes int64   `json:"remainingBytes"`
 	QuotaResetDate string  `json:"quotaResetDate"`
 }
+
+// ---------------------------------------------------------------------------
+// Batch download types (used by unarr migrate)
+// ---------------------------------------------------------------------------
+
+// BatchDownloadRequest sends a list of wanted items to queue for download.
+type BatchDownloadRequest struct {
+	Items         []WantedItem `json:"items"`
+	ExcludeHashes []string     `json:"excludeHashes,omitempty"` // blocklisted + already-downloaded hashes
+}
+
+// WantedItem represents a movie or series the user wants.
+type WantedItem struct {
+	TmdbID int    `json:"tmdbId,omitempty"`
+	ImdbID string `json:"imdbId,omitempty"`
+	Title  string `json:"title"`
+	Year   int    `json:"year,omitempty"`
+	Type   string `json:"type"` // "movie" or "show"
+}
+
+// BatchDownloadResponse reports the outcome of a batch download request.
+type BatchDownloadResponse struct {
+	Queued        int         `json:"queued"`
+	NotFound      int         `json:"notFound"`
+	AlreadyActive int         `json:"alreadyActive"`
+	Items         []BatchItem `json:"items"`
+}
+
+// BatchItem is the per-item result of a batch download.
+type BatchItem struct {
+	Title  string `json:"title"`
+	Status string `json:"status"` // "queued", "not_found", "already_active"
+}
+
+// ---------------------------------------------------------------------------
+// Debrid config types (used by unarr init/migrate)
+// ---------------------------------------------------------------------------
+
+// ConfigureDebridRequest configures a debrid provider.
+type ConfigureDebridRequest struct {
+	Provider string `json:"provider"` // "real-debrid", "alldebrid", "torbox", "premiumize"
+	Token    string `json:"token"`
+}
+
+// ConfigureDebridResponse is returned after configuring a debrid provider.
+type ConfigureDebridResponse struct {
+	Success bool         `json:"success"`
+	Account DebridAccount `json:"account"`
+	Error   string       `json:"error,omitempty"`
+}
+
+// DebridAccount holds verified debrid account info.
+type DebridAccount struct {
+	Valid     bool   `json:"valid"`
+	Premium   bool   `json:"premium"`
+	Username  string `json:"username"`
+	ExpiresAt string `json:"expiresAt,omitempty"`
+}
+
+// ---------------------------------------------------------------------------
+// Library sync types (used by unarr scan)
+// ---------------------------------------------------------------------------
+
+// LibrarySyncRequest sends scanned media items to the server.
+type LibrarySyncRequest struct {
+	Items       []LibrarySyncItem `json:"items"`
+	ScanPath    string            `json:"scanPath"`
+	IsLastBatch bool              `json:"isLastBatch"`
+}
+
+// LibrarySyncItem is a single scanned media file with ffprobe metadata.
+type LibrarySyncItem struct {
+	FilePath          string   `json:"filePath"`
+	FileName          string   `json:"fileName"`
+	FileSize          int64    `json:"fileSize,omitempty"`
+	Title             string   `json:"title"`
+	Year              string   `json:"year,omitempty"`
+	Season            int      `json:"season,omitempty"`
+	Episode           int      `json:"episode,omitempty"`
+	ContentType       string   `json:"contentType"`
+	Resolution        string   `json:"resolution,omitempty"`
+	VideoCodec        string   `json:"videoCodec,omitempty"`
+	HDR               string   `json:"hdr,omitempty"`
+	BitDepth          int      `json:"bitDepth,omitempty"`
+	AudioCodec        string   `json:"audioCodec,omitempty"`
+	AudioChannels     int      `json:"audioChannels,omitempty"`
+	AudioLanguages    []string `json:"audioLanguages,omitempty"`
+	SubtitleLanguages []string `json:"subtitleLanguages,omitempty"`
+	AudioTracks       any      `json:"audioTracks,omitempty"`
+	SubtitleTracks    any      `json:"subtitleTracks,omitempty"`
+	VideoInfo         any      `json:"videoInfo,omitempty"`
+}
+
+// LibrarySyncResponse is returned after syncing library items.
+type LibrarySyncResponse struct {
+	Synced  int `json:"synced"`
+	Matched int `json:"matched"`
+	Removed int `json:"removed"`
+}