fix dateconv test: correct JavaScript Date month parameter

JavaScript Date constructor uses 0-based months, so month 1 is February, not January.
Changed from month 1 to month 0 to properly test January 2nd, 2006.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <[email protected]>

Author: aster-void

packages/server/lib/utils/dateconv.test.ts

@@ -3,7 +3,7 @@ import { toHttpDate, toUnixTime } from "./dateconv.ts";
 
 describe("toHttpDate", () => {
   it("should format a date as an HTTP date string", () => {
-    const date = new Date(Date.UTC(2006, 1, 2, 15, 4, 5));
+    const date = new Date(Date.UTC(2006, 0, 2, 15, 4, 5));
     expect(toHttpDate(date)).toBe("Mon, 02 Jan 2006 15:04:05 GMT");
   });
 });