fix(ci): add Rust toolchain for Intel Mac builds (#459)

* fix(ci): add Rust toolchain for Intel Mac builds

real_ladybug package has no pre-built wheel for macOS Intel (x64),
requiring compilation from source. The build was hanging because
the Rust toolchain was not installed.

This adds dtolnay/rust-action@stable to the Intel Mac build jobs
in both release and beta-release workflows.

Also updates cache key to invalidate old caches that may have
incomplete packages.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

* fix: correct rust-toolchain action name (not rust-action)

---------

Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>

.github/workflows/beta-release.yml

@@ -89,11 +89,14 @@ jobs:
       - name: Install dependencies
         run: cd apps/frontend && npm ci
 
+      - name: Install Rust toolchain (for building native Python packages)
+        uses: dtolnay/rust-toolchain@stable
+
       - name: Cache bundled Python
         uses: actions/cache@v4
         with:
           path: apps/frontend/python-runtime
-          key: python-bundle-${{ runner.os }}-x64-3.12.8
+          key: python-bundle-${{ runner.os }}-x64-3.12.8-rust
           restore-keys: |
             python-bundle-${{ runner.os }}-x64-
 

.github/workflows/release.yml

@@ -43,11 +43,14 @@ jobs:
       - name: Install dependencies
         run: cd apps/frontend && npm ci
 
+      - name: Install Rust toolchain (for building native Python packages)
+        uses: dtolnay/rust-toolchain@stable
+
       - name: Cache bundled Python
         uses: actions/cache@v4
         with:
           path: apps/frontend/python-runtime
-          key: python-bundle-${{ runner.os }}-x64-3.12.8
+          key: python-bundle-${{ runner.os }}-x64-3.12.8-rust
           restore-keys: |
             python-bundle-${{ runner.os }}-x64-