feat: make kernel architecture-agnostic; primitive work on arm port

kernel/src/Arch/aarch64/InterruptFrame.hpp

@@ -0,0 +1,22 @@
+/*
+    * InterruptFrame.hpp
+    * aarch64 exception frame
+    * Copyright (c) 2026 Daniel Hammer
+*/
+
+#pragma once
+#include <cstdint>
+
+namespace Arch {
+
+    // What the exception vectors save before calling into C++.
+    struct PanicFrame {
+        uint64_t x[31];   // x0-x30
+        uint64_t sp;      // interrupted SP (SP_EL0 for EL0, else SP_EL1)
+        uint64_t elr;     // ELR_EL1: faulting/preferred-return PC
+        uint64_t spsr;    // SPSR_EL1
+        uint64_t esr;     // ESR_EL1: exception syndrome
+        uint64_t far;     // FAR_EL1: faulting address
+    };
+
+}