FEAT: Video Search In Discovery

discovery/internal/db/repositories/errors.go

@@ -7,3 +7,8 @@ import "errors"
 
 // ErrVideoNotFound reports that the catalogue holds no video with that id.
 var ErrVideoNotFound = errors.New("video not found")
+
+// ErrInvalidCursor reports that a paging cursor could not be read. It is the
+// caller's mistake, not a fault in the catalogue, so it must not reach the
+// handler as an indistinguishable query failure.
+var ErrInvalidCursor = errors.New("invalid cursor")