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

examples/ai_features.clj

@@ -0,0 +1,35 @@
+; AI Features Demo — requires API key (DEEPSEEK_API_KEY, OPENAI_API_KEY, or MIMO_API_KEY)
+; Run: ./cljnim repl  — then try the commands below
+;
+; Or compile/run: this file demonstrates the forms
+
+(println "=== Error Handling with try/catch/finally ===")
+
+(defn safe-divide [a b]
+  (try
+    (println "Dividing" a "by" b)
+    (/ a b)
+    (catch Exception e
+      (do
+        (println "Caught error:" (get e :message))
+        nil))
+    (finally
+      (println "Cleanup done"))))
+
+(println "Result:" (safe-divide 10 2))
+(println "Result:" (safe-divide 10 0))
+
+(println "")
+(println "=== AI Code Generation ===")
+(println "Use (ai/generate \"description\") in REPL")
+(println "Or CLI: ./cljnim ai 'function to reverse a list'")
+
+(println "")
+(println "=== AI Optimization ===")
+(println "Use (ai/optimize \"code\") in REPL")
+(println "Or REPL command: :optimize (defn sum [nums] (reduce + nums))")
+
+(println "")
+(println "=== AI Debugging ===")
+(println "Use (ai/debug expr) in REPL")
+(println "Or REPL command: :debug (+ 1 2 3)")