feat: switch text to UTF-8; add Unicode key events, dead keys & Czech layout; fix numpad navigation; add NumLock support

kernel/src/Sched/Scheduler.hpp

@@ -135,9 +135,13 @@ namespace Sched {
         uint8_t* inBuf = nullptr;    // 4KB ring: parent writes, child reads (getchar)
         volatile uint32_t inHead = 0;
         volatile uint32_t inTail = 0;
-        montauk::abi::KeyEvent keyBuf[64]; // parent injects, child reads (getkey/iskeyavailable)
         volatile uint32_t keyHead = 0;
         volatile uint32_t keyTail = 0;
+        // SYS_GETCHAR returns a key's UTF-8 encoding one byte per call; the
+        // bytes not handed out yet wait here.
+        uint8_t getcharUtf8[4] = {};
+        uint8_t getcharUtf8Len = 0;
+        uint8_t getcharUtf8Pos = 0;
         static constexpr uint32_t IoBufSize = 4096;
 
         // GUI terminal dimensions (set by desktop, read by SYS_TERMSIZE)