Fix canvas extension install links (#2109)

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Co-authored-by: Aaron Powell <me@aaron-powell.com>

website/src/scripts/pages/extensions-render.ts

@@ -104,7 +104,7 @@ export function renderExtensionsHtml(items: RenderableExtension[]): string {
           title="Copy install URL"
           ${installUrl ? "" : "disabled"}
         >
-          Install
+          Copy URL
         </button>
         ${
           sourceUrl

website/src/scripts/pages/extensions.ts

@@ -291,7 +291,7 @@ function setupActionHandlers(list: HTMLElement | null): void {
     }
     const success = await copyToClipboard(installUrl);
     showToast(
-      success ? "Install URL copied!" : "Failed to copy install URL",
+      success ? "Extension URL copied!" : "Failed to copy extension URL",
       success ? "success" : "error"
     );
     return;