Add notification tasks

Add three notification tasks that will branch from the inclusive gateway. Each represents a channel that *might* be activated.

Tasks to add

• "Send customer email" — for external-facing releases
• "Publish blog post" — if blog content exists
• "Update changelog" — always done (we'll handle that with conditions later)

Drag three task shapes from the palette and position them above, inline, and below the gateway to give each branch visual space.

> 💡 With three outgoing paths from an inclusive gateway, between 1 and 3 of them will activate per run. The conditions on each arrow determine which.