feat(extension): add Firefox WebExtension support

- Add a neutral WebExtension API adapter that uses Firefox browser.* or Chromium chrome.* without mutating globals.
- Switch extension runtime code to the adapter and add Firefox-specific typings for tabs, windows, tab groups, storage, scripting, and native messaging ports.
- Fix Firefox temporary add-on instructions to load the packaged manifest with background.scripts instead of the Chromium service worker manifest.
- Detect Firefox in clients.list via runtime.getBrowserInfo and keep Chromium user-agent fallback support.
- Make navigate.open wait briefly for Firefox to replace initial about:blank with the requested URL.
- Add JS coverage for API selection, clients.list browser detection, and Firefox navigate.open URL polling.
- Bump package and extension version to 0.15.2.

extension/src/commands/navigation.ts

@@ -1,3 +1,5 @@
+import { webExtApi as api } from '../browser-api';
+import type { Tab } from '../types';
 import { getActiveTab, getAliases, groupTabs as groupTabIds, isBrowserErrorUrl, resolveGroupId, tabInfo, updateTabGroup } from '../core';
 import { CommandGroup } from '../classes/CommandGroup';
 import type { CommandEntry } from '../classes/CommandGroup';
@@ -26,19 +28,19 @@ export class NavigationCommands extends CommandGroup {
       const entry = Object.entries(aliases).find(([, v]) => v === windowName);
       if (entry) windowId = parseInt(entry[0]);
     }
-    const tab = await chrome.tabs.create({ url, active: Boolean(focus) && !background, windowId });
+    const tab = await api.tabs.create({ url, active: Boolean(focus) && !background, windowId });
     if (groupNameOrId != null) {
       let groupId;
       try {
         groupId = await resolveGroupId(groupNameOrId);
         // Close any blank placeholder tabs that were created when the group was made
-        const groupTabs = await chrome.tabs.query({ groupId });
+        const groupTabs = await api.tabs.query({ groupId });
         const placeholders = groupTabs.filter(t =>
           t.id !== tab.id &&
           (t.url === "chrome://newtab/" || t.url === "about:blank" || t.pendingUrl === "chrome://newtab/")
         );
         await groupTabIds({ tabIds: [tab.id], groupId });
-        if (placeholders.length) await chrome.tabs.remove(placeholders.map(t => t.id));
+        if (placeholders.length) await api.tabs.remove(placeholders.map(t => t.id));
       } catch (e) {
         if (!(e instanceof Error) || !e.message.startsWith("No tab group found")) throw e;
         // Group doesn't exist — create it with the tab already in it
@@ -46,14 +48,37 @@ export class NavigationCommands extends CommandGroup {
         await updateTabGroup(groupId, { title: String(groupNameOrId) });
       }
     }
-    return { id: tab.id, url: tab.url };
+    const loadedTab = await this.waitForOpenedTabUrl(tab.id, url, tab);
+    return { id: loadedTab.id, url: loadedTab.url || loadedTab.pendingUrl || url };
+  }
+
+  private async waitForOpenedTabUrl(tabId: number, targetUrl: string, initialTab: Tab): Promise<Tab> {
+    const initialUrl = initialTab.url || initialTab.pendingUrl || "";
+    if (this.isOpenedTabUrlReady(initialUrl, targetUrl)) return initialTab;
+
+    const deadline = Date.now() + 2000;
+    while (Date.now() < deadline) {
+      const current = await api.tabs.get(tabId);
+      const currentUrl = current.url || current.pendingUrl || "";
+      if (this.isOpenedTabUrlReady(currentUrl, targetUrl)) return current;
+      await new Promise(r => setTimeout(r, 50));
+    }
+
+    return api.tabs.get(tabId);
+  }
+
+  private isOpenedTabUrlReady(currentUrl: string, targetUrl: string): boolean {
+    if (!currentUrl) return false;
+    if (currentUrl === targetUrl || currentUrl.startsWith(targetUrl)) return true;
+    if (targetUrl === "about:blank" || targetUrl === "chrome://newtab/") return currentUrl === targetUrl;
+    return currentUrl !== "about:blank" && currentUrl !== "chrome://newtab/";
   }
 
   private async navTo({ tabId, url }: NavToArgs) {
-    const tab = await chrome.tabs.update(tabId, { url });
+    const tab = await api.tabs.update(tabId, { url });
     const deadline = Date.now() + 1000;
     while (tabId && Date.now() < deadline) {
-      const current = await chrome.tabs.get(tabId);
+      const current = await api.tabs.get(tabId);
       const currentUrl = current.url || current.pendingUrl || "";
       if (currentUrl === url || currentUrl.startsWith(url)) {
         return { id: current.id, url: currentUrl };
@@ -65,35 +90,35 @@ export class NavigationCommands extends CommandGroup {
 
   private async navReload({ tabId }: NavTabArgs, bypassCache: boolean) {
     const tab = tabId ? { id: tabId } : await getActiveTab();
-    await chrome.tabs.reload(tab.id, { bypassCache });
+    await api.tabs.reload(tab.id, { bypassCache });
     return { tabId: tab.id };
   }
 
   private async navBack({ tabId }: NavTabArgs) {
     const tab = tabId ? { id: tabId } : await getActiveTab();
-    await chrome.tabs.goBack(tab.id);
+    await api.tabs.goBack(tab.id);
     return { tabId: tab.id };
   }
 
   private async navForward({ tabId }: NavTabArgs) {
     const tab = tabId ? { id: tabId } : await getActiveTab();
-    await chrome.tabs.goForward(tab.id);
+    await api.tabs.goForward(tab.id);
     return { tabId: tab.id };
   }
 
   private async navFocus({ pattern }: NavFocusArgs) {
     // If pattern is a plain integer, treat it as a tab ID
     const asInt = parseInt(pattern);
-    let match: chrome.tabs.Tab | undefined;
+    let match: Tab | undefined;
     if (!isNaN(asInt) && String(asInt) === String(pattern)) {
-      match = await chrome.tabs.get(asInt);
+      match = await api.tabs.get(asInt);
     } else {
-      const all = await chrome.tabs.query({});
+      const all = await api.tabs.query({});
       match = all.find(t => (t.url && t.url.includes(pattern)) || (t.pendingUrl && t.pendingUrl.includes(pattern)));
     }
     if (!match) return null;
-    await chrome.windows.update(match.windowId, { focused: true });
-    await chrome.tabs.update(match.id, { active: true });
+    await api.windows.update(match.windowId, { focused: true });
+    await api.tabs.update(match.id, { active: true });
     return { id: match.id, url: match.url || match.pendingUrl, title: match.title };
   }
 
@@ -102,7 +127,7 @@ export class NavigationCommands extends CommandGroup {
     const deadline = Date.now() + timeout;
     const interval = 200;
     while (Date.now() < deadline) {
-      const t = await chrome.tabs.get(tab.id);
+      const t = await api.tabs.get(tab.id);
       const currentUrl = t.url || t.pendingUrl || "";
       if (isBrowserErrorUrl(currentUrl)) {
         throw new Error(`Tab ${tab.id} is showing an error page while waiting for load (${currentUrl})`);