fix(plugins): enforce rustc compatibility

BREAKING CHANGE: API v4+ plugin packages must declare the exact rustc version used to build the binary.

Refs #901

docs/plugin-template/.github/workflows/release.yml

@@ -36,7 +36,7 @@ jobs:
         run: |
           mkdir -p dist
           cp target/release/*.${{ matrix.ext }} "dist/${{ matrix.asset }}"
-          cp plugin.toml dist/plugin.toml
+          sed "s|__RUSTC_VERSION__|$(rustc --version)|" plugin.toml > dist/plugin.toml
       - uses: softprops/action-gh-release@v2
         with:
           files: |

docs/plugin-template/README.md

@@ -28,7 +28,8 @@ folder into a new repo and rename the placeholders.
 cargo build --release
 mkdir -p "<config>/OpenCADStudio/plugins/opencad.my_plugin"
 cp target/release/*my_plugin*.so "<config>/OpenCADStudio/plugins/opencad.my_plugin/"
-cp plugin.toml                    "<config>/OpenCADStudio/plugins/opencad.my_plugin/"
+sed "s|__RUSTC_VERSION__|$(rustc --version)|" plugin.toml > \
+  "<config>/OpenCADStudio/plugins/opencad.my_plugin/plugin.toml"
 ```
 
 Restart Open CAD Studio: the ribbon tab appears and `MP_` commands route to your

docs/plugin-template/plugin.toml

@@ -8,7 +8,8 @@ license = "GPL-3.0-only"
 repository = "your-account/your-plugin-repo"
 
 [opencad]
-api_version = 3
+api_version = 4
+rustc_version = "__RUSTC_VERSION__"
 ribbon_order = 60
 command_prefixes = ["MP_"]
 xdata_apps = ["MYPLUGIN_RECORD"]