Initial commit: Klammertext source distribution

Curated source subset assembled by klammertext-dev's doc/make_dist.sh: the Klammermachine (mac), the Standard Klammer Set (sks), the commands (com), editor plugins and install guides (doc), a test subset (tst), and lib/bin placeholders. Builds with 'make -C com'.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

sks/kutil/klammer_base.h

@@ -0,0 +1,31 @@
+#pragma once
+
+#include <iostream>
+#include <string>
+#include <map>
+#include <filesystem>
+#include "eval.h"
+#include "machine.h"
+
+#define VISIBLE __attribute__ ((visibility ("default")))
+
+using argmap = std::map<std::string, std::string>;
+
+class Klammer_base {
+public:
+    Klammer_base(Machine& machine)
+        : m_machine(machine)
+        {};
+    virtual ~Klammer_base() {};
+
+    std::string get(std::string);
+    std::string get(const char* name);
+    virtual std::string html();
+    virtual std::string tex();
+    virtual std::string txt();
+
+    std::string result();
+    void show(std::string klammer_name);
+
+    Machine m_machine;
+};