refactor: use git_override for rules_rust wasip2 support

- Replace local_path_override with git_override pointing to avrabe/rules_rust
- Use feature/wasi-p2-support branch with minimal wasip2 patches
- Remove large third_party/rules_rust_patched directory (3,423 files)
- Add patch file and documentation for maintainability
- Much cleaner approach than carrying full patched codebase

Author: avrabe

MODULE.bazel

@@ -13,7 +13,7 @@ bazel_dep(name = "rules_rust", version = "0.62.0")
 git_override(
     module_name = "rules_rust",
     remote = "https://github.com/avrabe/rules_rust.git",
-    commit = "HEAD",  # Update this to specific commit hash once patch is applied
+    commit = "feature/wasi-p2-support",
 )
 bazel_dep(name = "bazel_skylib", version = "1.7.1")
 bazel_dep(name = "platforms", version = "0.0.11")

PATCH_README.md

@@ -0,0 +1,56 @@
+# rules_rust WASI Support Patch
+
+This repository uses a fork of rules_rust with minimal patches to support WASI target triples.
+
+## What's Patched
+
+**File**: `rust/platform/triple.bzl`  
+**Changes**: Added support for 2-component WASI target triples
+
+### The Problem
+rules_rust expects target triples to have 3+ components (e.g., `x86_64-unknown-linux-gnu`), but WASI targets use 2-component format:
+- `wasm32-wasip1` (WASI Preview 1)
+- `wasm32-wasip2` (WASI Preview 2)
+
+### The Solution
+Convert 2-component WASI targets to standard 3-component format:
+- `wasm32-wasip1` → `wasm32-unknown-wasi`  
+- `wasm32-wasip2` → `wasm32-unknown-wasi`
+- `wasm32-wasip3` → `wasm32-unknown-wasi` (future support)
+
+## Applying the Patch
+
+1. Clone the rules_rust fork:
+   ```bash
+   git clone https://github.com/avrabe/rules_rust.git
+   cd rules_rust
+   ```
+
+2. Apply the patch:
+   ```bash
+   git apply wasip2-support.patch
+   ```
+
+3. Commit and push:
+   ```bash
+   git add rust/platform/triple.bzl
+   git commit -m "feat: add support for wasm32-wasip2 target triples
+
+   - Handle 2-component WASI target triples in triple.bzl
+   - Convert wasm32-wasip1, wasm32-wasip2, wasm32-wasip3 to standard format
+   - Enable WASI Preview 2 builds with rules_rust compatibility"
+   git push origin main
+   ```
+
+4. Update the commit hash in `MODULE.bazel`:
+   ```python
+   git_override(
+       module_name = "rules_rust",
+       remote = "https://github.com/avrabe/rules_rust.git", 
+       commit = "abc123...",  # Use the actual commit hash
+   )
+   ```
+
+## Status
+
+This is a minimal, safe patch that only affects target triple parsing. The changes are expected to be upstreamed to the main rules_rust repository eventually.