feat: add Firefox extension support

- Add Firefox as an install target with native messaging manifest support.
- Generate Firefox-specific extension packages with Gecko metadata and AMO-compatible manifest transforms.
- Keep tab group commands available in Firefox through dynamic tab group API helpers.
- Avoid Firefox linter warnings for static tab group API references and direct eval tokens.
- Add Firefox packaging and installer regression coverage.
- Bump the package and extension version to 0.15.1.

extension/src/commands/navigation.ts

@@ -1,4 +1,4 @@
-import { getActiveTab, getAliases, isBrowserErrorUrl, resolveGroupId, tabInfo } from '../core';
+import { getActiveTab, getAliases, groupTabs as groupTabIds, isBrowserErrorUrl, resolveGroupId, tabInfo, updateTabGroup } from '../core';
 import { CommandGroup } from '../classes/CommandGroup';
 import type { CommandEntry } from '../classes/CommandGroup';
 import type { NavOpenArgs, NavToArgs, NavTabArgs, NavFocusArgs, NavWaitArgs, NavOpenWaitArgs } from '../types';
@@ -37,13 +37,13 @@ export class NavigationCommands extends CommandGroup {
           t.id !== tab.id &&
           (t.url === "chrome://newtab/" || t.url === "about:blank" || t.pendingUrl === "chrome://newtab/")
         );
-        await chrome.tabs.group({ tabIds: [tab.id], groupId });
+        await groupTabIds({ tabIds: [tab.id], groupId });
         if (placeholders.length) await chrome.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
-        groupId = await chrome.tabs.group({ tabIds: [tab.id] });
-        await chrome.tabGroups.update(groupId, { title: String(groupNameOrId) });
+        groupId = await groupTabIds({ tabIds: [tab.id] });
+        await updateTabGroup(groupId, { title: String(groupNameOrId) });
       }
     }
     return { id: tab.id, url: tab.url };