fix(extension): handle browser error pages gracefully

- Treat chrome error page script failures as transient during injection retries.
- Return safe fallback values for read-only DOM commands when tabs land on browser error pages.
- Improve URL watch handling by checking pending URLs and reporting last seen URL/status on timeout.
- Bump package and extension version to 0.9.6 and add regression coverage for error-page behavior.

extension/src/core.ts

@@ -5,12 +5,22 @@ export async function getProfileAlias() {
   return profileAlias || "default";
 }
 
+export function isErrorPageScriptError(error) {
+  const message = String(error?.message || error || "");
+  return message.includes("error page") || message.includes("chrome-error://chromewebdata");
+}
+
+export function isTransientScriptError(error) {
+  const message = String(error?.message || error || "");
+  return message.includes("Frame with ID") || message.includes("No tab with id") || isErrorPageScriptError(error);
+}
+
 export async function executeScript(options, retries = 3) {
   for (let i = 0; i < retries; i++) {
     try {
       return await chrome.scripting.executeScript(options);
     } catch (e) {
-      if (i < retries - 1 && e.message && (e.message.includes("Frame with ID") || e.message.includes("No tab with id")) && !e.message.includes("error page")) {
+      if (i < retries - 1 && isTransientScriptError(e)) {
         await new Promise(r => setTimeout(r, 300));
         continue;
       }