feat: SMP stage 2, lock-free fast paths (GetTime, GetProcessId, DebugPutchar, no-op Yield), storm checks yield equivalence

crates/kernel/src/smp.rs

@@ -79,6 +79,15 @@ impl<P: Platform> Kernel<P> {
         }
     }
 
+    /// The highest priority waiting in `core`'s run queue.
+    pub fn highest_waiting(&self, core: CoreId) -> Option<Priority> {
+        self.scheduler.highest_waiting(core)
+    }
+
+    pub fn thread_priority(&self, tid: ThreadId) -> Option<Priority> {
+        self.threads.get(tid).ok().map(|t| t.priority())
+    }
+
     /// What `core` should do after an IPI: keep running its thread, or
     /// switch to a higher-priority one now waiting. When it has no thread
     /// (it was idle, or its thread was destroyed) the caller picks the