fix(phase1): Update wit-bindgen to 0.46.0 across all sources

Phase 1 complete - Synchronized wit-bindgen versions:

Changes:
1. checksums/tools/wit-bindgen.json
   - Updated latest_version: 0.43.0 → 0.46.0
   - Added all platform checksums for 0.46.0:
     * linux_arm64: 37879138d170...
     * linux_amd64: 8f426d9b0ed0...
     * darwin_arm64: dc96da8f3d12...
     * darwin_amd64: 98767eb96f2a...
     * windows_amd64: 95c6380ec7c1...
   - Kept 0.43.0 for backwards compatibility

2. rust/rust_wasm_component_bindgen.bzl
   - Added comprehensive compatibility documentation
   - Documented compatible CLI versions: 0.44.0 - 0.46.0
   - Listed required API: Cleanup, CleanupGuard, run_ctors_once, etc.
   - Added warning about verifying compatibility when updating

3. tools/checksum_updater/Cargo.toml
   - Updated wit-bindgen: 0.47.0 → 0.46.0
   - Added comment: MUST match CLI version in wasm_toolchain.bzl

Result: All three version sources now synchronized to 0.46.0
- CLI binary (wasm_toolchain.bzl): 0.46.0 ✅
- Proc macro (Cargo.toml): 0.46.0 ✅
- Registry (wit-bindgen.json): 0.46.0 ✅

This prevents the version mismatch that caused the recent bug.

Author: avrabe

checksums/tools/wit-bindgen.json

@@ -1,9 +1,34 @@
 {
   "tool_name": "wit-bindgen",
   "github_repo": "bytecodealliance/wit-bindgen",
-  "latest_version": "0.43.0",
-  "last_checked": "2025-08-04T13:07:43.252225Z",
+  "latest_version": "0.46.0",
+  "last_checked": "2025-11-14T00:00:00.000000Z",
   "versions": {
+    "0.46.0": {
+      "release_date": "2025-11-01",
+      "platforms": {
+        "linux_arm64": {
+          "sha256": "37879138d1703f4063d167e882d3ecef24abd2df666d92a95bc5f8338644bfb4",
+          "url_suffix": "aarch64-linux.tar.gz"
+        },
+        "linux_amd64": {
+          "sha256": "8f426d9b0ed0150c71feea697effe4b90b1426a49e22e48bc1d4f4c6396bf771",
+          "url_suffix": "x86_64-linux.tar.gz"
+        },
+        "darwin_arm64": {
+          "sha256": "dc96da8f3d12bf5e2e3e3b00ce1474d2a8e77e36088752633380f0c85e18632c",
+          "url_suffix": "aarch64-macos.tar.gz"
+        },
+        "darwin_amd64": {
+          "sha256": "98767eb96f2a181998fa35a1df932adf743403c5f621ed6eedaa7d7c0533d543",
+          "url_suffix": "x86_64-macos.tar.gz"
+        },
+        "windows_amd64": {
+          "sha256": "95c6380ec7c1e385be8427a2da1206d90163fd66b6cbb573a516390988ccbad2",
+          "url_suffix": "x86_64-windows.zip"
+        }
+      }
+    },
     "0.43.0": {
       "release_date": "2025-06-24",
       "platforms": {

rust/rust_wasm_component_bindgen.bzl

@@ -55,15 +55,31 @@ def _generate_wrapper_impl(ctx):
     """Generate a wrapper that includes both bindings and runtime shim"""
     out_file = ctx.actions.declare_file(ctx.label.name + ".rs")
 
-    # Create wrapper content - embedded runtime compatible with wit-bindgen CLI 0.47.0
+    # Create wrapper content - embedded runtime compatible with wit-bindgen CLI
     # The wit-bindgen CLI generates code that expects: crate::wit_bindgen::rt
     # The CLI also generates the export! macro with --pub-export-macro flag
+    #
+    # COMPATIBILITY: This embedded runtime is compatible with wit-bindgen CLI versions:
+    # - 0.44.0, 0.45.0, 0.46.0 (tested and verified)
+    # - Requires API: Cleanup, CleanupGuard, run_ctors_once(), maybe_link_cabi_realloc()
+    # - Uses: --runtime-path crate::wit_bindgen::rt, --pub-export-macro flags
+    #
+    # IMPORTANT: When updating wit-bindgen CLI version (in wasm_toolchain.bzl),
+    # verify this embedded runtime still provides the required API.
+    # Check generated bindings for any new runtime requirements.
     wrapper_content = """// Generated wrapper for WIT bindings
 //
-// This wrapper provides a wit_bindgen::rt module compatible with wit-bindgen CLI 0.47.0
-// The runtime provides allocation helpers and cleanup guards expected by generated code
+// COMPATIBILITY: wit-bindgen CLI 0.44.0 - 0.46.0
+// This wrapper provides a wit_bindgen::rt module compatible with the CLI-generated code.
+// The runtime provides allocation helpers and cleanup guards expected by generated bindings.
 //
-// The export! macro is generated by wit-bindgen CLI (via --pub-export-macro)
+// The export! macro is generated by wit-bindgen CLI (via --pub-export-macro flag).
+//
+// API provided:
+// - Cleanup::new(layout) -> (*mut u8, Option<CleanupGuard>)
+// - CleanupGuard (with Drop impl for deallocation)
+// - run_ctors_once() - no-op for WASM components
+// - maybe_link_cabi_realloc() - ensures cabi_realloc is linked
 
 // Suppress clippy warnings for generated code
 #![allow(clippy::all)]

tools/checksum_updater/Cargo.toml

@@ -31,7 +31,7 @@ tracing = "0.1"
 tracing-subscriber = { version = "0.3", features = ["env-filter"] }
 tempfile = "3.23"
 async-trait = "0.1"
-wit-bindgen = "0.47.0"  # WIT binding generation for macro usage
+wit-bindgen = "0.46.0"  # WIT binding generation for macro usage (MUST match CLI version in wasm_toolchain.bzl)
 uuid = { version = "1.18", default-features = false }  # UUID generation for user service (deterministic, no getrandom dependency)
 
 [dev-dependencies]