Code Review: Embed Deno Runtime for Extension Bundling

This PR is well-designed and follows project guidelines. Approving with minor suggestions.

✅ Domain-Driven Design

The implementation correctly applies DDD patterns:

• DenoVersion (src/domain/runtime/deno_version.ts:24) - Proper value object: immutable, equality by value, factory methods
• DenoRuntime (src/domain/runtime/deno_runtime.ts:27) - Clean port interface in domain layer
• EmbeddedDenoRuntime (src/infrastructure/runtime/embedded_deno_runtime.ts:59) - Infrastructure adapter properly separated from domain
• Dependency Injection - UserModelLoader accepts DenoRuntime via constructor, enabling testability

✅ Code Quality

• All new .ts files include AGPLv3 headers
• Named exports throughout (no default exports)
• TypeScript strict mode compliance
• The single deno-lint-ignore no-explicit-any at embedded_deno_runtime.ts:67 is justified since Deno.build.standalone isn't in Deno's type definitions

✅ Test Coverage

Unit tests provided for:

• DenoVersion (deno_version_test.ts)
• bundleExtension (bundle_test.ts)
• EmbeddedDenoRuntime (embedded_deno_runtime_test.ts)
• UserModelLoader updates (27 existing tests updated + 1 new TypeScript-specific syntax test)

✅ Security

• Downloads from trusted source (GitHub releases) during compile only, not runtime
• No command injection vectors (subprocess args are hardcoded strings)
• Embedded binary verification via version marker

💡 Suggestions (non-blocking)

1. Bundle cache cleanup - Consider adding a way to clear .swamp/bundles/ when deno versions change, since bundles compiled with one deno version might not work with another. Not critical since the mtime check handles source changes.

2. Error context in download_deno.ts - Line 855: When unzip fails, the error message could include the stdout for additional context:

   throw new Error(`unzip failed: ${stderr}\nstdout: ${stdout}`);

3. Windows platform support - The download_deno.ts uses unzip which may not be available on Windows. Consider documenting this or adding a fallback. This only affects cross-compilation scenarios.

Overall, excellent work! The architecture cleanly separates domain concerns from infrastructure, and the implementation is robust.