fix: Remove incorrect export macro re-export from wrapper

The wit-bindgen CLI generates the export! macro itself (via --pub-export-macro flag).
We should NOT re-export it from wit-bindgen-rt, which doesn't have it in v0.39.0.

The wrapper should only provide:
  - pub use wit_bindgen_rt as wit_bindgen;  (for wit_bindgen::rt module)

The export! macro is generated by the CLI and included in the bindings.

This fixes: error[E0432]: unresolved import `wit_bindgen_rt::export`

Author: claude

docs/embedded_runtime_fix.md

@@ -41,18 +41,17 @@ This is automatically available as `@crates//:wit-bindgen-rt` through the crates
 - `wit-bindgen` = Procedural macro crate for `generate!()` macro
 - `wit-bindgen-rt` = Runtime crate for CLI-generated bindings (what we need)
 
-#### 2. Simplified Runtime Wrapper (rust/rust_wasm_component_bindgen.bzl:58-79)
+#### 2. Simplified Runtime Wrapper (rust/rust_wasm_component_bindgen.bzl:58-78)
 
 **Before**: 114 lines of embedded runtime stubs
-**After**: 6 lines of simple re-exports
+**After**: 1 line of simple re-export
 
 ```rust
-// Re-export wit-bindgen-rt as wit_bindgen to provide proper runtime implementation
-// The wit-bindgen CLI generates code that expects: crate::wit_bindgen::rt
+// Re-export wit-bindgen-rt as wit_bindgen to provide the runtime module
+// This provides wit_bindgen::rt with proper allocator integration
 pub use wit_bindgen_rt as wit_bindgen;
 
-// Re-export the export macro at crate level for convenience
-pub use wit_bindgen_rt::export;
+// Note: export! macro is generated by wit-bindgen CLI (via --pub-export-macro)
 ```
 
 #### 3. Added Dependencies to Bindings Libraries (lines 326, 337)

rust/rust_wasm_component_bindgen.bzl

@@ -57,25 +57,24 @@ def _generate_wrapper_impl(ctx):
 
     # Create wrapper content - re-export wit-bindgen-rt as wit_bindgen
     # The wit-bindgen CLI generates code that expects: crate::wit_bindgen::rt
-    # wit-bindgen-rt provides the runtime support (export macro, allocator, etc)
+    # The CLI also generates the export! macro with --pub-export-macro flag
     wrapper_content = """// Generated wrapper for WIT bindings
 //
 // This wrapper re-exports wit-bindgen-rt as wit_bindgen to provide the runtime
 // at the path expected by wit-bindgen CLI (--runtime-path crate::wit_bindgen::rt)
+//
+// The export! macro is generated by wit-bindgen CLI (via --pub-export-macro)
 
 // Suppress clippy warnings for generated code
 #![allow(clippy::all)]
 #![allow(unused_imports)]
 #![allow(dead_code)]
 
-// Re-export wit-bindgen-rt as wit_bindgen to provide proper runtime implementation
-// This provides the export! macro, rt module with correct allocator integration
+// Re-export wit-bindgen-rt as wit_bindgen to provide the runtime module
+// This provides wit_bindgen::rt with proper allocator integration
 pub use wit_bindgen_rt as wit_bindgen;
 
-// Re-export the export macro at crate level for convenience
-pub use wit_bindgen_rt::export;
-
-// Generated bindings follow:
+// Generated bindings follow (including export! macro):
 """
 
     # Concatenate wrapper content with generated bindings