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)

src/builtin/dirstack.rs

@@ -127,7 +127,8 @@ pub fn pushd(node: Node, io_stack: &mut IoStack, job: &mut JobBldr) -> ShResult<
     unreachable!()
   };
 
-  let (argv, _guard) = setup_builtin(argv, job, Some((io_stack, node.redirs)))?;
+  let (argv, _guard) = setup_builtin(Some(argv), job, Some((io_stack, node.redirs)))?;
+  let argv = argv.unwrap();
 
   let mut dir = None;
   let mut rotate_idx = None;
@@ -213,7 +214,8 @@ pub fn popd(node: Node, io_stack: &mut IoStack, job: &mut JobBldr) -> ShResult<(
     unreachable!()
   };
 
-  let (argv, _guard) = setup_builtin(argv, job, Some((io_stack, node.redirs)))?;
+  let (argv, _guard) = setup_builtin(Some(argv), job, Some((io_stack, node.redirs)))?;
+  let argv = argv.unwrap();
 
   let mut remove_idx = None;
   let mut no_cd = false;
@@ -316,7 +318,8 @@ pub fn dirs(node: Node, io_stack: &mut IoStack, job: &mut JobBldr) -> ShResult<(
     unreachable!()
   };
 
-  let (argv, _guard) = setup_builtin(argv, job, Some((io_stack, node.redirs)))?;
+  let (argv, _guard) = setup_builtin(Some(argv), job, Some((io_stack, node.redirs)))?;
+  let argv = argv.unwrap();
 
   let mut abbreviate_home = true;
   let mut one_per_line = false;