fix: add missing token-refresh-timer module

Timer wrapper around refreshTokenProactively() — runs immediately
on plugin load, then every 6 hours. Imported by index.ts but was
never committed.

Author: calltelemetry-jason

src/infra/token-refresh-timer.ts

@@ -0,0 +1,51 @@
+import type { OpenClawPluginApi } from "openclaw/plugin-sdk";
+import { refreshTokenProactively } from "../api/linear-api.js";
+
+const REFRESH_INTERVAL_MS = 6 * 60 * 60 * 1000; // 6 hours
+
+let timer: ReturnType<typeof setInterval> | null = null;
+
+/**
+ * Start the proactive token refresh timer.
+ * Runs immediately on start, then every 6 hours.
+ */
+export function startTokenRefreshTimer(
+  api: OpenClawPluginApi,
+  pluginConfig?: Record<string, unknown>,
+): void {
+  // Run immediately
+  doRefresh(api, pluginConfig);
+
+  // Then schedule periodic refresh
+  timer = setInterval(() => doRefresh(api, pluginConfig), REFRESH_INTERVAL_MS);
+  // Don't keep the process alive just for this timer
+  if (timer && typeof timer === "object" && "unref" in timer) {
+    timer.unref();
+  }
+}
+
+/**
+ * Stop the proactive token refresh timer.
+ */
+export function stopTokenRefreshTimer(): void {
+  if (timer) {
+    clearInterval(timer);
+    timer = null;
+  }
+}
+
+async function doRefresh(
+  api: OpenClawPluginApi,
+  pluginConfig?: Record<string, unknown>,
+): Promise<void> {
+  try {
+    const result = await refreshTokenProactively(pluginConfig);
+    if (result.refreshed) {
+      api.logger.info(`Token refresh: ${result.reason}`);
+    } else {
+      api.logger.debug?.(`Token refresh skipped: ${result.reason}`);
+    }
+  } catch (err) {
+    api.logger.warn(`Token refresh failed: ${err}`);
+  }
+}