feat(mediator): publish the initial mediator package #2

Closes #1

Behaviour

@chrismichaelps/pudu-lang-mediator 0.1.0 for Pudu 0.1.3: in-process messaging between the parts of a program.

• Kinds — Request.kind (answers a value), Request.command (answers ()), Notification.kind, and Stream.kind; typed identities made once and shared.
• Pipelines — per-kind and open behaviors, pre- and post-processors, exception handlers, and exception actions, composed once at build time in one documented order; stream behaviors that may wrap the sink.
• Publishing — Sequential (default), Continuing, Parallel, Bounded, or a custom Publishing.Strategy.
• Mediator — build reports every registration problem at once; send, resolve, publish, stream, collect, reader, and untyped dispatch, broadcast, and streamEnvelope through envelopes.
• Seams — Sender and Publisher traits implemented by the mediator; typed context items and cooperative cancellation.
• Integrations — validation (pudu-lang-validator), structured logging (pudu-lang-log), and resilience (pudu-lang-resilience) behaviors, the only modules importing other packages.

Values cross untyped boundaries through slots, never casts; a twin kind under a registered name answers Mismatched instead of reaching the wrong handler.

Verification

Against the published 0.1.3 compiler, from a clean pudu install --locked:

• pudu check, pudu fmt --check, and pudu lint are clean over src test tools examples.
• pudu test test: 24 suites pass, 235 assertions, including concurrency (parallel peaks, bounded worker limits, crash containment, reader back-pressure and close), the vault parity suite, and an integration scenario.
• Every program under examples/ answers 0.
• pudu run tools/Mutate.pudu --domain --threshold 100: killed 12, survived 0.