Add array support for local/export/readonly builtins

Add array length syntax ${arr[#]}

Map read path now expands variables before splitting on ., fixing map "$node" with dotted paths

Map assignment path uses quote-aware token splitting, enabling quoted keys like "--type="

Completion errors now display above prompt instead of being overwritten

Fix nested if/fi parser bug when closing keywords appear on separate lines

Add QuoteState enum, replacing ad-hoc quote tracking booleans across lexer, highlighter, and expansion

Add split_tk_at/split_tk for quote-aware token splitting with span preservation

Refactor setup_builtin to accept optional argv for deferred expansion

Add ariadne dependency (not yet wired up)

Cargo.lock

@@ -61,6 +61,16 @@ dependencies = [
  "windows-sys 0.61.2",
 ]
 
+[[package]]
+name = "ariadne"
+version = "0.6.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8454c8a44ce2cb9cc7e7fae67fc6128465b343b92c6631e94beca3c8d1524ea5"
+dependencies = [
+ "unicode-width",
+ "yansi",
+]
+
 [[package]]
 name = "arrayvec"
 version = "0.7.6"
@@ -451,6 +461,7 @@ dependencies = [
 name = "shed"
 version = "0.3.0"
 dependencies = [
+ "ariadne",
  "bitflags",
  "clap",
  "env_logger",