feat: add async runtime documentation chapter

- Add new chapter 13 covering Promise-based async native runtime
- Update wiki workflow to include async runtime documentation
- Add cross-references in embedding SDK documentation
- Improve cranelift backend error handling with better diagnostics for missing value_map entries

Author: darmie

.github/workflows/wiki.yml

@@ -36,6 +36,7 @@ jobs:
           cp book/10-packaging-distribution.md wiki/10-Packaging-Distribution.md
           cp book/11-hir-builder.md wiki/11-HIR-Builder.md
           cp book/12-embedding-sdk.md wiki/12-Embedding-SDK.md
+          cp book/13-async-runtime.md wiki/13-Async-Runtime.md
 
           # Fix internal links for wiki format
           sed -i 's|\./01-introduction\.md|01-Introduction|g' wiki/*.md
@@ -50,6 +51,7 @@ jobs:
           sed -i 's|\./10-packaging-distribution\.md|10-Packaging-Distribution|g' wiki/*.md
           sed -i 's|\./11-hir-builder\.md|11-HIR-Builder|g' wiki/*.md
           sed -i 's|\./12-embedding-sdk\.md|12-Embedding-SDK|g' wiki/*.md
+          sed -i 's|\./13-async-runtime\.md|13-Async-Runtime|g' wiki/*.md
 
       - name: Upload wiki
         uses: Andrew-Chen-Wang/github-wiki-action@v4

book/12-embedding-sdk.md

@@ -1026,6 +1026,7 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
 
 ## Next Steps
 
+- See [Async Runtime](./13-async-runtime.md) for detailed async/Promise documentation
 - See [Grammar Syntax](./04-grammar-syntax.md) for writing `.zyn` grammars
 - See [TypedAST](./06-typed-ast.md) for understanding the intermediate representation
 - See [ZRTL Plugins](./10-packaging-distribution.md) for creating native runtime libraries