core: route_from runs a plugin from another .wasm file (seam for activation)

Stop tracking examples/notes/Cargo.lock.

cli/src/routing.rs

@@ -51,6 +51,20 @@ impl Host {
         method: String,
         params: Value,
         detached: bool,
+    ) -> NativeFuture {
+        self.route_from(caller, id, method, params, detached, None)
+    }
+    /// Like `route`, but a WASI process runs the component at `wasm` instead
+    /// of the current `plugin.wasm` of its plugin. Activation uses this to
+    /// call `rpc.discover` on a candidate file.
+    pub(crate) fn route_from(
+        &self,
+        caller: String,
+        id: Option<Value>,
+        method: String,
+        params: Value,
+        detached: bool,
+        wasm: Option<std::path::PathBuf>,
     ) -> NativeFuture {
         let host = self.clone();
         Box::pin(async move {
@@ -87,7 +101,7 @@ impl Host {
                     .0
                     .components
                     .load(
-                        host.0.world.plugin_dir(plugin).join("plugin.wasm"),
+                        wasm.unwrap_or_else(|| host.0.world.plugin_dir(plugin).join("plugin.wasm")),
                         host.0.runtime.clone(),
                     )
                     .await?;