v0.29.1

Language

• Add type aliases for naming existing types, including parameterized
  aliases such as type Dict[K(Hashable)] = dict[K, str], so annotations,
  casts, imports, witness resolution, generated docs, and completion can use
  alias names while the compiler expands them for checking. [#3026]
• Treat top-level statement initiators such as actor, class, extension,
  from, import, protocol, and type as soft keywords, so they can be
  used as parameter or local names when they are not starting a declaration or
  import. [#3027]

Compiler & Build

• Commit cached module-interface rows synchronously before reporting a module's
  front pass as complete, making .tydb writes part of front-pass completion
  and reporting write failures as normal compiler diagnostics. [#3019]
• Compile pure lambdas that return tuples without crashing eta reduction when
  the lambda parameter itself is not tuple-typed. [#3024]

CLI & Project Workflow

• Show local project signatures without the project-prefix in acton sig
  output, including imports and nested type and witness references. [#3030]

Runtime & Standard Library

• Fix str.splitlines() linebreak detection so newline and CRLF-separated
  strings split into the expected lines. [#3023]
• Register failed continuations for serialization and reject unregistered
  classes during serialization, preventing silent DB recovery corruption when
  exceptions propagate to waiting actors. [#3031]