docs: onboarding v2, widgets for telegram workflows, hero widget (#138)

docs/how-to/topics.md

@@ -2,6 +2,9 @@
 
 Topics bind Telegram **forum threads** to a project/branch context. Each topic keeps its own session and default agent, which is ideal for teams or multi-project work.
 
+!!! tip "Workspace workflow"
+    If you chose the **workspace** workflow during [onboarding](../tutorials/install.md), topics are already enabled. This guide covers advanced topic configuration and usage.
+
 ## Why use topics
 
 - Keep each thread tied to a repo + branch
@@ -15,6 +18,13 @@ Topics bind Telegram **forum threads** to a project/branch context. Each topic k
 - The bot is an **admin** with **Manage Topics** permission
 - If you want topics in project chats, set `projects.<alias>.chat_id`
 
+!!! note "Setting up workspace from scratch"
+    If you didn't choose workspace during onboarding and want to enable topics now:
+
+    1. Create a group and enable topics in group settings
+    2. Add your bot as admin with "Manage Topics" permission
+    3. Update your config to enable topics (see below)
+
 ## Enable topics
 
 ```toml