feat: expose linked TinyBus module entry point

[senamakel]

Summary

• Add opt-in tinyhosts/static-link using TinyBus module_export_optional_static!, which selects dynamic exports by default and a Rust-addressable module in static builds.
• Expose tinyhosts::linked_module() for direct host registration.
• Pin TinyBus commit 433d9ed and use =0.1.2 registry dependency identities, with local Cargo patches for standalone builds.

Related issue

Depends on tinyhumansai/tinybus#29, which builds on merged #28. Ready condition: #29 is merged, this gitlink is reachable from upstream TinyBus, and CI passes. This PR remains a draft until then.

API or behavior changes

Additive public linked_module() under static-link. The default loadable module path and wire contract are unchanged.

Validation

• cargo fmt --manifest-path Cargo.toml --all -- --check
• cargo check --manifest-path Cargo.toml -p tinyhosts --offline
• cargo check --manifest-path Cargo.toml -p tinyhosts --features static-link --offline
• Full clippy, build, test, and coverage suites have not been rerun on this final commit.

Tests

The two feature builds verify both TinyBus macro expansions and the public root reexport. No runtime behavior changes were added in this package.

Documentation

The feature and root entry point are documented in this PR and by TinyBus #29.

Checklist

• The change is focused on static module registration.
• No lint levels were relaxed in this update.
• No secrets or environment contents are included.

[coderabbitai]

Important

Draft PR not reviewed

Draft PRs are not automatically reviewed by default.

• Trigger a manual review

To automatically review draft PRs, update your CodeRabbit configuration:

reviews:
  auto_review:
    drafts: true

---

_{Comment @coderabbitai help to get the list of available commands.}