fix(naming): parse bare bracketed IMDb IDs ([tt10011226]/{tt...})

Folders tagged with a bare IMDb id in brackets (Plex/Kodi style, e.g.
'17 Blocks (2021) [tt10011226]') had the id silently dropped — folderIDPattern
needs an 'imdb-' prefix and trailingImdbIDPattern needs an un-bracketed trailing
tt-id. Recognize bracketed bare tt-ids so these items get the trusted-ID match
path instead of falling to title+year scoring.

internal/naming/folderid.go

@@ -13,6 +13,11 @@ var folderIDPattern = regexp.MustCompile(`[{\[](tmdb|tmdbid|imdb|imdbid|tvdb|tvd
 var trailingImdbIDPattern = regexp.MustCompile(`(?i)(?:^|\s)(tt\d{7,8})$`)
 var trailingNumericIDPattern = regexp.MustCompile(`(?:^|\s)(\d+)$`)
 
+// bracketedBareImdbPattern matches a bare IMDb id wrapped in brackets without a
+// provider prefix, e.g. [tt10011226] or {tt0095016} (Plex/Kodi-style tags). A
+// tt-prefixed number is unambiguously IMDb.
+var bracketedBareImdbPattern = regexp.MustCompile(`(?i)[{\[](tt\d{7,8})[}\]]`)
+
 // ParseStructuredFolderIDs extracts only explicit structured provider IDs from
 // a folder or file name, such as {tmdb-27205} or [imdbid-tt1375666}. It does
 // not consider trailing bare IDs or folderType-based heuristics.
@@ -52,6 +57,10 @@ func ParseFolderIDs(folderName string, folderType string) *FolderIDHints {
 		return hints
 	}
 
+	if m := bracketedBareImdbPattern.FindStringSubmatch(folderName); m != nil {
+		return &FolderIDHints{ImdbID: strings.ToLower(m[1])}
+	}
+
 	trimmed := strings.TrimSpace(folderName)
 	if m := trailingImdbIDPattern.FindStringSubmatch(trimmed); m != nil {
 		return &FolderIDHints{ImdbID: strings.ToLower(m[1])}

internal/naming/folderid_test.go

@@ -0,0 +1,29 @@
+package naming
+
+import "testing"
+
+func TestParseFolderIDs_BracketedBareImdb(t *testing.T) {
+	cases := []struct {
+		name, folder, wantImdb string
+	}{
+		{"square brackets", "17 Blocks (2021) [tt10011226]", "tt10011226"},
+		{"curly braces", "Some Show {tt1234567}", "tt1234567"},
+		{"8-digit tt", "Movie (2024) [tt12345678]", "tt12345678"},
+	}
+	for _, c := range cases {
+		got := ParseFolderIDs(c.folder, "movie")
+		if got == nil || got.ImdbID != c.wantImdb {
+			t.Errorf("%s: ParseFolderIDs(%q) = %+v, want ImdbID=%q", c.name, c.folder, got, c.wantImdb)
+		}
+	}
+	// must NOT change existing behavior:
+	if got := ParseFolderIDs("Movie [imdb-tt1375666]", "movie"); got == nil || got.ImdbID != "tt1375666" {
+		t.Errorf("structured imdb regressed: %+v", got)
+	}
+	if got := ParseFolderIDs("Some Movie (2020) [BB]", "movie"); got != nil {
+		t.Errorf("non-tt bracket tag must not parse as id, got %+v", got)
+	}
+	if got := ParseFolderIDs("17 Blocks (2021)", "movie"); got != nil {
+		t.Errorf("no-id folder must return nil, got %+v", got)
+	}
+}