fix: platform transition now correctly selects wasm32-wasip2

- Update to commit 2a8c7b8e6fdf0dbdf1c4914f897e3f95f674e275 with repository context fix
- Use @rules_rust//rust/platform constraints for WASI version differentiation
- Platform transition successfully resolves to wasm32-wasip2 (not wasip1)

The toolchain is now correctly selecting wasm32-wasip2 as evidenced by:
external/rules_rust++rust+rust_macos_aarch64__wasm32-wasip2__stable_tools

Fixes #2

Author: avrabe

MODULE.bazel

@@ -12,7 +12,7 @@ bazel_dep(name = "rules_rust", version = "0.62.0")
 # Git override to use rules_rust fork with wasm32-wasip2 support  
 git_override(
     module_name = "rules_rust",
-    commit = "54f0df94dccdd34fa35a22adfb7b4626e85d99b4",  # Commit with WASI constraint system fixes
+    commit = "2a8c7b8e6fdf0dbdf1c4914f897e3f95f674e275",  # Latest commit with repository context fix
     remote = "https://github.com/avrabe/rules_rust.git",
 )
 

platforms/BUILD.bazel

@@ -1,30 +1,14 @@
 """Platform definitions for WASM targets"""
 
-# Custom WASI version constraints to distinguish between preview versions
-constraint_setting(
-    name = "wasi_version",
-    default_constraint_value = ":wasi_preview_1",
-    visibility = ["//visibility:public"],
-)
-
-constraint_value(
-    name = "wasi_preview_1",
-    constraint_setting = ":wasi_version", 
-    visibility = ["//visibility:public"],
-)
-
-constraint_value(
-    name = "wasi_preview_2",
-    constraint_setting = ":wasi_version",
-    visibility = ["//visibility:public"],
-)
+# Note: WASI version constraints are now provided by the patched rules_rust
+# at @rules_rust//rust/platform:wasi_preview_1 and :wasi_preview_2
 
 platform(
     name = "wasm32-wasi",
     constraint_values = [
         "@platforms//cpu:wasm32",
         "@platforms//os:wasi",
-        ":wasi_preview_1",
+        "@rules_rust//rust/platform:wasi_preview_1",
     ],
     visibility = ["//visibility:public"],
 )
@@ -43,7 +27,7 @@ platform(
     constraint_values = [
         "@platforms//cpu:wasm32",
         "@platforms//os:wasi",
-        ":wasi_preview_1",
+        "@rules_rust//rust/platform:wasi_preview_1",
     ],
     visibility = ["//visibility:public"],
 )
@@ -53,7 +37,7 @@ platform(
     constraint_values = [
         "@platforms//cpu:wasm32",
         "@platforms//os:wasi", 
-        ":wasi_preview_2",
+        "@rules_rust//rust/platform:wasi_preview_2",
     ],
     visibility = ["//visibility:public"],
 )