refactor: split main runtime wrappers into focused modules

src/main/runtime/mpv-osd-log.ts

@@ -0,0 +1,42 @@
+import type { MpvRuntimeClientLike } from '../../core/services/mpv';
+
+export function createAppendToMpvLogHandler(deps: {
+  logPath: string;
+  dirname: (targetPath: string) => string;
+  mkdirSync: (targetPath: string, options: { recursive: boolean }) => void;
+  appendFileSync: (
+    targetPath: string,
+    data: string,
+    options: { encoding: 'utf8' },
+  ) => void;
+  now: () => Date;
+}) {
+  return (message: string): void => {
+    try {
+      deps.mkdirSync(deps.dirname(deps.logPath), { recursive: true });
+      deps.appendFileSync(deps.logPath, `[${deps.now().toISOString()}] ${message}\n`, {
+        encoding: 'utf8',
+      });
+    } catch {
+      // best-effort logging
+    }
+  };
+}
+
+export function createShowMpvOsdHandler(deps: {
+  appendToMpvLog: (message: string) => void;
+  showMpvOsdRuntime: (
+    mpvClient: MpvRuntimeClientLike | null,
+    text: string,
+    fallbackLog: (line: string) => void,
+  ) => void;
+  getMpvClient: () => MpvRuntimeClientLike | null;
+  logInfo: (line: string) => void;
+}) {
+  return (text: string): void => {
+    deps.appendToMpvLog(`[OSD] ${text}`);
+    deps.showMpvOsdRuntime(deps.getMpvClient(), text, (line) => {
+      deps.logInfo(line);
+    });
+  };
+}