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

template/sysroot/include/gui/clipboard.hpp

@@ -9,12 +9,32 @@
 #include <montauk/syscall.h>
 #include <montauk/string.h>
 #include <montauk/heap.h>
+#include <montauk/utf8.h>
 
 namespace gui {
 
+    // The clipboard carries UTF-8. Text that is not well-formed (legacy
+    // Windows-1252 bytes) is converted on the way in and on the way out, so
+    // every reader can assume valid UTF-8.
+    inline char* clipboard_utf8_copy(const char* text, int len, int* out_len) {
+        int cap = len * 3 + 1;   // each stray byte grows to at most 3
+        char* out = (char*)montauk::malloc(cap);
+        if (!out) return nullptr;
+        *out_len = montauk::utf8::normalize(text, len, out, cap);
+        return out;
+    }
+
     inline bool clipboard_set_text(const char* text, int len) {
         if (len < 0) return false;
         if (len > 0 && text == nullptr) return false;
+        if (len > 0 && !montauk::utf8::valid(text, len)) {
+            int fixed_len = 0;
+            char* fixed = clipboard_utf8_copy(text, len, &fixed_len);
+            if (!fixed) return false;
+            bool ok = montauk::clipboard_set_text(fixed, (uint32_t)fixed_len) == 0;
+            montauk::mfree(fixed);
+            return ok;
+        }
         return montauk::clipboard_set_text(text, (uint32_t)len) == 0;
     }
 
@@ -53,6 +73,14 @@ namespace gui {
         }
 
         text[actual_len] = '\0';
+        if (!montauk::utf8::valid(text, (int)actual_len)) {
+            int fixed_len = 0;
+            char* fixed = clipboard_utf8_copy(text, (int)actual_len, &fixed_len);
+            montauk::mfree(text);
+            if (!fixed) return nullptr;
+            text = fixed;
+            actual_len = (uint32_t)fixed_len;
+        }
         if (out_len) *out_len = (int)actual_len;
         if (out_serial) *out_serial = serial;
         return text;