Width and height argtypes, kdesc --argtypes from ref/, txt @define/@left_right/@columns, kdiag --check value validation (from dev d6993110e9b3)

Also: the klammertext argtype (descriptions kept as source), txt table
wrapping and :hpos/:offset, @c between ‹ ›, txt section headings, the
ktext newline-only trim, capitalize(), and the argtype test suite.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

com/kdesc.cpp

@@ -177,6 +177,14 @@ void show_unicode_examples()
     std::cout << "\n" << M.apply(text_target()) << "\n\n";
 }
 
+void show_argtype_definitions()
+{
+    Machine M;
+    M.read(M.m_state.value("KLAMMERTEXT_HOME") + "/ref/ref.k");
+    M.read_string("@argtype_definitions@");
+    std::cout << "\n" << M.apply(text_target()) << "\n\n";
+}    
+
 int main(int argc, char* argv[])
 {
     try {
@@ -224,10 +232,9 @@ int main(int argc, char* argv[])
             show_unicode_examples();
         }
 
+
         if (p("argtypes")) {
-            Argtype_registry argtypes;
-            std::cout << boldblack << "\nStandard klammer argument types\n" << black;
-            std::cout << argtypes.describe() << "\n";
+            show_argtype_definitions();
         }
 
         if (args.given("katoms")) {

com/ktext.cpp

@@ -70,7 +70,12 @@ int main(int argc, char* argv[])
             M.read(fs::path(p));
         }
 
-        std::string result = trim(M.apply(target));
+        // Trim NEWLINES only, as Machine::apply itself does: a leading space
+        // is content under txt -- the indent of a block that opens the
+        // document (a table, a definition list) -- and trim() took it off
+        // the first line alone, every other line keeping its indent
+        // (TODO #60, 2026-09-13).
+        std::string result = trim_char(M.apply(target), '\n');
         if (display_only && !result.empty()) {
             std::cout << result << "\n";
         } else if (!result.empty()) {