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

kernel/src/Drivers/USB/HidKeyboard.cpp

@@ -223,6 +223,12 @@ namespace Drivers::USB::HidKeyboard {
             if (caps && base >= 'a' && base <= 'z') upper = !shift;
             ascii = upper ? g_ScancodeToAsciiShifted[scancode] : base;
         }
+        // Num Lock off: the keypad is navigation keys, which type nothing.
+        // (Only keypad usages get here with these scancodes: the dedicated
+        // navigation keys are nonChar already.)
+        if (!Drivers::PS2::Keyboard::GetNumLock() &&
+            Drivers::PS2::Keyboard::IsKeypadNavScancode(scancode))
+            ascii = 0;
 
         Drivers::PS2::Keyboard::KeyEvent event = {
             .Scancode = scancode,
@@ -367,10 +373,14 @@ namespace Drivers::USB::HidKeyboard {
                 uint8_t scancode = g_HidToScancode[key];
                 if (scancode != 0) {
                     InjectKey(scancode, true, modifiers, IsNonCharKey(key), IsExtendedKey(key));
-                    g_RepeatKey = key;
-                    g_RepeatStartMs = now;
-                    g_LastRepeatMs = 0;
                     newKeyPressed = true;
+                    // Lock keys toggle once per press; repeating them while
+                    // held would flip Caps/Num/Scroll Lock on and off.
+                    if (key != 0x39 && key != 0x53 && key != 0x47) {
+                        g_RepeatKey = key;
+                        g_RepeatStartMs = now;
+                        g_LastRepeatMs = 0;
+                    }
                 }
             }
         }