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

programs/src/dialogs/filedialog.cpp

@@ -261,15 +261,16 @@ void fit_text_start(const char* src, char* out, int out_len, int max_px) {
     // Grid labels must fit their cell in pixels. Character-count truncation is
     // insufficient for the proportional system font and lets wide names paint
     // over the adjacent label.
-    int keep = montauk::slen(src);
-    if (keep > out_len - 3) keep = out_len - 3;
+    int slen = montauk::slen(src);
+    int keep = slen;
+    if (keep > out_len - 3) keep = montauk::utf8::floor_boundary(src, slen, out_len - 3);
     while (keep > 0) {
         for (int i = 0; i < keep; i++) out[i] = src[i];
         out[keep] = '.';
         out[keep + 1] = '.';
         out[keep + 2] = '\0';
         if (text_width(out) <= max_px) return;
-        keep--;
+        keep = montauk::utf8::prev_boundary(src, keep);
     }
 
     safe_copy(out, out_len, "..");
@@ -1216,14 +1217,14 @@ void handle_file_key(const montauk::abi::KeyEvent& key) {
         return;
     }
 
-    if (key.scancode == 0x4B || key.scancode == 0x48) {
+    if (montauk::nav_scancode(key) == 0x4B || montauk::nav_scancode(key) == 0x48) {
         if (st->selected > 0) st->selected--;
         else if (st->entry_count > 0) st->selected = 0;
         file_ensure_selected_visible(st);
         return;
     }
 
-    if (key.scancode == 0x4D || key.scancode == 0x50) {
+    if (montauk::nav_scancode(key) == 0x4D || montauk::nav_scancode(key) == 0x50) {
         if (st->selected < st->entry_count - 1) st->selected++;
         else if (st->entry_count > 0) st->selected = st->entry_count - 1;
         file_ensure_selected_visible(st);