Support some, ok and err wrappers and untyped function inputs

Track the LScript changes since the grammar was first written:

- some, ok and err are reserved prefix operators and wrapper patterns;
  the old |.some/|.ok/|.err forms and postfix/prefix ! are rejected
- function literal inputs may omit their type annotation, and tuple
  components may omit theirs; an empty typed tuple pattern is now just
  the unit pattern
- migrate fixtures, corpus, queries, CST contract and Rust tests

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

test/fixtures/valid/pipelines.ls

@@ -15,9 +15,9 @@ commented := 'value' # an inline comment preserves continuation
 computed := 1 + 2
 ->to_str
 
-fallible: i32 -> i32 ! Error: @ value: i32 { value! }
+fallible: i32 -> i32 ! Error: @ value: i32 { ok value }
 
 propagate: i32 -> i32 ! Error: @ value: i32 {
     result := {value->fallible}?
-    result!
+    ok result
 }