Pure formatting pass from `cargo fmt --all`. No logic changes. Separating
this out so the 1.9 release feature commits that follow show only their
intentional edits.
SchemaType enum with inline syntax parsing: "string", "string?",
"list<number>", "map<string>", nested generics. WorkflowSchema
validates inputs/outputs against type declarations at both compile
time and runtime. 39 tests for parse and validate paths.
