fix(naming): numeric-only titles are not bare provider IDs

'86' / '22 7' were parsed as trailing tvdb ids, tripping the trusted-ID gate
so the correct title match was rejected. Require a letter in the name before
treating a trailing number as a bare id.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

internal/naming/folderid.go

@@ -3,6 +3,7 @@ package naming
 import (
 	"regexp"
 	"strings"
+	"unicode"
 )
 
 // folderIDPattern matches patterns like [tmdbid-27205], {tmdb-27205},
@@ -66,12 +67,27 @@ func ParseFolderIDs(folderName string, folderType string) *FolderIDHints {
 		return nil
 	}
 
+	// A bare trailing number is only an ID when appended to a real title. If the
+	// name has no letters (e.g. "86", "22 7"), it's a numeric title, not an ID.
+	if !containsLetter(trimmed) {
+		return nil
+	}
+
 	if strings.EqualFold(strings.TrimSpace(folderType), "series") {
 		return &FolderIDHints{TvdbID: id}
 	}
 	return &FolderIDHints{TmdbID: id}
 }
 
+func containsLetter(s string) bool {
+	for _, r := range s {
+		if unicode.IsLetter(r) {
+			return true
+		}
+	}
+	return false
+}
+
 func looksLikeYear(value string) bool {
 	return len(value) == 4 && value >= "1800" && value <= "2100"
 }

internal/naming/folderid_numeric_test.go

@@ -0,0 +1,25 @@
+package naming
+
+import "testing"
+
+func TestParseFolderIDs_NumericTitleIsNotAnID(t *testing.T) {
+	// Numeric-only anime titles must NOT be parsed as a bare trailing tvdb/tmdb id.
+	if got := ParseFolderIDs("86", "series"); got != nil {
+		t.Errorf(`ParseFolderIDs("86","series") = %+v, want nil`, got)
+	}
+	if got := ParseFolderIDs("22 7", "series"); got != nil {
+		t.Errorf(`ParseFolderIDs("22 7","series") = %+v, want nil`, got)
+	}
+
+	// A real bare trailing id with title text must still be parsed.
+	got := ParseFolderIDs("Some Show 81189", "series")
+	if got == nil || got.TvdbID != "81189" {
+		t.Errorf(`ParseFolderIDs("Some Show 81189","series") = %+v, want TvdbID="81189"`, got)
+	}
+
+	// Structured tags must still win regardless of letters.
+	got = ParseFolderIDs("{tmdb-27205}", "movies")
+	if got == nil || got.TmdbID != "27205" {
+		t.Errorf(`ParseFolderIDs("{tmdb-27205}","movies") = %+v, want TmdbID="27205"`, got)
+	}
+}