docs(thread): document group IDs in --notify help text

`tdc thread reply/create --notify` already accepts custom group IDs
(partitioned via resolveNotifyIds → groups), but the help text only
mentioned "user IDs". Since Comms group IDs are non-numeric base58
strings that look nothing like user IDs, the capability was effectively
undiscoverable from --help. Mention groups in both option descriptions.

No behaviour change.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: lmjabreu

src/commands/thread/index.ts

@@ -50,7 +50,7 @@ Examples:
             withUnvalidatedChoices(
                 new Option(
                     '--notify <recipients>',
-                    'Notification recipients: EVERYONE, EVERYONE_IN_THREAD, or comma-separated user IDs (default: EVERYONE_IN_THREAD)',
+                    'Notification recipients: EVERYONE, EVERYONE_IN_THREAD, or comma-separated user and/or group IDs (default: EVERYONE_IN_THREAD)',
                 ),
                 ['EVERYONE', 'EVERYONE_IN_THREAD'],
             ),
@@ -76,7 +76,7 @@ Examples:
     thread
         .command('create <channel-ref> <title> [content]')
         .description('Create a new thread in a channel')
-        .option('--notify <recipients>', 'Comma-separated user IDs to notify')
+        .option('--notify <recipients>', 'Comma-separated user and/or group IDs to notify')
         .option(
             '--unarchive',
             'Unarchive after creation so the thread appears in your Inbox (overrides userSettings.unarchiveNewThreads when false)',