feat: add fullscreen TUI and project updates

- New TUI screens: Main Menu, Compile, Run, REPL, AI Generator, AI Settings, Help
- AI configuration persisted in ~/.config/cljnim/config.json
- Added illwill dependency for terminal UI
- Updated experiments, examples, docs, and core modules

experiments/native-lib/test_client/main.c

@@ -0,0 +1,24 @@
+#include <stdio.h>
+
+// Declarations from the shared library
+extern int c_square(int x);
+extern int c_factorial(int n);
+extern int c_add(int a, int b);
+extern const char* c_greet(const char* name);
+
+// Nim runtime init
+extern void NimMain(void);
+
+int main(void) {
+    NimMain();
+
+    printf("=== Clojure/Nim Native Library Test ===\n\n");
+
+    printf("c_square(7) = %d\n", c_square(7));
+    printf("c_add(10, 20) = %d\n", c_add(10, 20));
+    printf("c_factorial(5) = %d\n", c_factorial(5));
+    printf("c_greet(\"World\") = %s\n", c_greet("World"));
+
+    printf("\nAll tests passed! Clojure in a .so file.\n");
+    return 0;
+}