tweaks (#1142)

* opt: unused layout

* mod: semantics

* opt: DanmakuMsg type

* opt: avoid cast

* opt: unnecessary_lambdas

* opt: use isEven

* opt: logger

* opt: invalid common page

* tweak

* opt: unify DynController

pubspec.lock

@@ -900,7 +900,7 @@ packages:
     source: hosted
     version: "1.5.0"
   http2:
-    dependency: transitive
+    dependency: "direct main"
     description:
       name: http2
       sha256: "382d3aefc5bd6dc68c6b892d7664f29b5beb3251611ae946a98d35158a82bbfa"