Enhance logging and task management; enable trace facility, add scheduler state logging, and improve shutdown handling

software/nova64.zig

@@ -5,6 +5,10 @@ pub fn log(message: []const u8) void {
     nova64_log(message.ptr);
 }
 
-pub fn yield(timeout_ms: u32) void {
+pub fn sleep(timeout_ms: u32) void {
     nova64_yield(timeout_ms);
 }
+
+pub fn yield() void {
+    nova64_yield(0);
+}