VS Code: Reload window on first activation event (#4989)

CLOSE
https://linear.app/sourcegraph/issue/CODY-3007/new-sidebar-ui-does-not-get-picked-up-on-extension-reload

Add a condition to check if `newSidebarChatUI_isReloaded` has been set
before or not.

If not, reload the window to ensure the new webview is registered before
the extension host is activated.

After discussing with @kalanchan and @vovakulikov , we think this is a
better approach than showing the CTA to ask users to reload without
knowing if the user has reloaded or not.

## Test plan

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https://docs-legacy.sourcegraph.com/dev/background-information/testing_principles.
-->

Green CI - The extension should not be affected by this change and work
as expected.

## Changelog

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https://www.notion.so/sourcegraph/Writing-a-changelog-entry-dd997f411d524caabf0d8d38a24a878c
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vscode/src/main.ts

@@ -95,6 +95,17 @@ export async function start(
     context: vscode.ExtensionContext,
     platform: PlatformContext
 ): Promise<vscode.Disposable> {
+    // NOTE: Hack to ensure the window is reloaded when extension is restarted after upgrade
+    //  to get the updated sidebar chat UI. Can be removed after the next release (1.28).
+    if (
+        !context.globalState.get('newSidebarChatUI_isReloaded', false) &&
+        process.env.CODY_TESTING !== 'true'
+    ) {
+        // First activation, set the flag and then reload the window
+        await context.globalState.update('newSidebarChatUI_isReloaded', true)
+        await vscode.commands.executeCommand('workbench.action.reloadWindow')
+    }
+
     const isExtensionModeDevOrTest =
         context.extensionMode === vscode.ExtensionMode.Development ||
         context.extensionMode === vscode.ExtensionMode.Test