test: refactor and format test files

- Update `game.test.ts` to use `_ctx` when `this` is not required
- Fix type assertion in `boop.test.ts`
- Update `command-runner.test.ts` to use `parseCommandSchema` in prompt
  tests
- Reformat `middleware.test.ts` to use double quotes and consistent
  indentation

tests/core/game.test.ts

@@ -60,15 +60,12 @@ describe("createGameContext", () => {
     const registry = createGameCommandRegistry();
     const ctx = createGameContext(registry);
 
-    registry.register(
-      "test <value>",
-      async function (this: CommandRunnerContext<IGameContext>, _ctx, value) {
-        return this.prompt(
-          createPromptDef("prompt <answer>"),
-          (answer) => answer,
-        );
-      },
-    );
+    registry.register("test <value>", async function (_ctx, value) {
+      return _ctx.prompt(
+        createPromptDef("prompt <answer>"),
+        (answer) => answer,
+      );
+    });
 
     const promptPromise = new Promise<PromptEvent>((resolve) => {
       ctx._commands.on("prompt", resolve);