add: WebDL / TVRip media types and filename-token override

Source kind is now declared per-file via a `dvd` / `bluray` / `webdl` /
`tvrip` token in the basename (case-insensitive, word-bounded). Matches
the existing `tt…` / `tvm…` filename convention. When no token is
present, falls back to the pixel-count guess in DetectMediaType, which
still only chooses between DVD and Blu-ray.

The parsed media type drives both ORIGINAL_MEDIA_TYPE in the muxed
metadata and the CRF/preset profile used for encoding. EncodingConfig
gains `webdl` and `tvrip` sub-blocks with conservative defaults
(WebDL 30/3, TVRip 32/2); user can override in config.yaml.

Manual updated with the new tokens, config fields, and pipeline
description.

internal/metadata/metadata.go

@@ -19,9 +19,10 @@ const (
 )
 
 var (
-	imdbRegex = regexp.MustCompile(`tt(\d+)`)
-	tvmRegex  = regexp.MustCompile(`(?i)tvm(\d+)`)
-	seRegex   = regexp.MustCompile(`(?i)s(\d+)e(\d+)`)
+	imdbRegex      = regexp.MustCompile(`tt(\d+)`)
+	tvmRegex       = regexp.MustCompile(`(?i)tvm(\d+)`)
+	seRegex        = regexp.MustCompile(`(?i)s(\d+)e(\d+)`)
+	mediaTypeRegex = regexp.MustCompile(`(?i)\b(dvd|bluray|webdl|tvrip)\b`)
 )
 
 type OMDbResponse struct {
@@ -86,6 +87,28 @@ func parseInt(s string) int {
 	return n
 }
 
+// ParseMediaType looks for a `.dvd.` / `.bluray.` / `.webdl.` / `.tvrip.`
+// token (case-insensitive) in the filename and returns the matching MediaType.
+// Returns an empty MediaType if no token is found, so the caller can fall back
+// to the pixel-count heuristic.
+func ParseMediaType(filename string) types.MediaType {
+	m := mediaTypeRegex.FindStringSubmatch(strings.TrimSuffix(filename, ".mkv"))
+	if m == nil {
+		return ""
+	}
+	switch strings.ToLower(m[1]) {
+	case "dvd":
+		return types.MediaTypeDVD
+	case "bluray":
+		return types.MediaTypeBluRay
+	case "webdl":
+		return types.MediaTypeWebDL
+	case "tvrip":
+		return types.MediaTypeTVRip
+	}
+	return ""
+}
+
 func (c *Client) FetchMovieMetadata(imdbID string) (*types.Metadata, error) {
 	url := fmt.Sprintf("%s?i=%s&apikey=%s", omdbAPIURL, imdbID, c.omdbAPIKey)