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/examples/math.clj

@@ -0,0 +1,18 @@
+(ns math)
+
+(defn square [x]
+  (* x x))
+
+(defn cube [x]
+  (* x x x))
+
+(defn add [a b]
+  (+ a b))
+
+(defn greet [name]
+  (str "Hello, " name "!"))
+
+(defn factorial [n]
+  (if (= n 0)
+    1
+    (* n (factorial (- n 1)))))