feat(Sky): Add webview post-message bridge for extension communication

Add a new handler for `sky://webview/post-message` that dispatches `cel:webview:post-message` custom events to the renderer. This bridges the raw extension `postMessage` path from Cocoon (gRPC `OnDidReceiveMessage` + `PostWebviewMessage`) which carries the `{ handle, message }` shape, distinct from the existing `sky://webview/message` handler that uses the workbench-RPC `{ panelId, method, params }` shape.

This enables extension-hosted code to communicate back to the Sky webview UI components through the established custom event system.

Author: NikolaRHristov

Source/Function/SkyBridge.ts

@@ -2330,6 +2330,11 @@ export async function InstallSkyBridge(): Promise<void> {
 	}
 
 	// ---- Webview ----
+	// `sky://webview/message` carries the workbench-RPC shape
+	// `{ panelId, method, params }` (Mountain `RPC/CocoonService/mod.rs`
+	// `webview.postMessage` arm). The raw extension `postMessage` path
+	// (gRPC `OnDidReceiveMessage` + `PostWebviewMessage`) emits the
+	// `{ handle, message }` shape on `sky://webview/post-message`.
 	await Register(
 		"sky://webview/message",
 		({ panelId, method, params }: any) => {
@@ -2341,6 +2346,17 @@ export async function InstallSkyBridge(): Promise<void> {
 		},
 	);
 
+	await Register(
+		"sky://webview/post-message",
+		({ handle, message }: any) => {
+			document.dispatchEvent(
+				new CustomEvent("cel:webview:post-message", {
+					detail: { handle, message },
+				}),
+			);
+		},
+	);
+
 	await Register("sky://webview/dispose", ({ panelId }: any) => {
 		document.dispatchEvent(
 			new CustomEvent("cel:webview:dispose", { detail: { panelId } }),