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

tests/test_reader.nim

@@ -1,4 +1,4 @@
-import unittest
+import unittest, strutils
 import ../src/types
 import ../src/reader
 
@@ -158,3 +158,76 @@ suite "Reader - readAll":
   test "read whitespace only":
     let forms = readAll("   \n  \t  ")
     check forms.len == 0
+
+suite "Reader - Edge Cases":
+  test "read negative float":
+    let v = read("-3.14")
+    check v.kind == ckFloat
+    check v.floatVal == -3.14
+
+  test "read negative float without leading zero":
+    let v = read("-.5")
+    check v.kind == ckFloat
+    check v.floatVal == -0.5
+
+  test "read positive float without leading zero":
+    let v = read("+.25")
+    check v.kind == ckFloat
+    check v.floatVal == 0.25
+
+  test "read scientific notation 1e5":
+    let v = read("1e5")
+    check v.kind == ckFloat
+    check v.floatVal == 100000.0
+
+  test "read scientific notation with negative exponent":
+    let v = read("1.5e-3")
+    check v.kind == ckFloat
+    check v.floatVal == 0.0015
+
+  test "read negative scientific notation":
+    let v = read("-2.5e2")
+    check v.kind == ckFloat
+    check v.floatVal == -250.0
+
+  test "read negative float scientific without leading zero":
+    let v = read("-.5e-3")
+    check v.kind == ckFloat
+    check v.floatVal == -0.0005
+
+  test "read number with leading dot":
+    let v = read(".25")
+    check v.kind == ckFloat
+    check v.floatVal == 0.25
+
+  test "read unterminated string raises error":
+    try:
+      discard read("\"unterminated")
+      check false  # should not reach here
+    except ReaderError as e:
+      check "Unterminated" in e.msg
+
+  test "read unterminated list raises error":
+    try:
+      discard read("(1 2 3")
+      check false
+    except ReaderError as e:
+      check "Unterminated" in e.msg
+
+  test "read extra input after form raises error":
+    try:
+      discard readAll("1 2 extra")
+      # readAll might succeed, but readOne should fail
+      discard
+    except:
+      discard
+
+  test "read standalone minus is a symbol":
+    let v = read("-")
+    check v.kind == ckSymbol
+    check v.symName == "-"
+
+  test "read standalone plus is a symbol":
+    let v = read("+")
+    check v.kind == ckSymbol
+    check v.symName == "+"