docs: add "One Card per Step" Studio page (AGE-107)

Document the merge of the task and agent nodes into a single step card on
the Studio canvas. Written as evergreen present-tense feature docs with a
dated rollout banner (June 24th) for the pre-launch customer announcement;
the banner is the only time-bound content and is flagged for removal after
ship. Added in edge + v1.14.7 across en, pt-BR, ko, and ar, with nav entries
in docs.json and three canvas/editor/swap screenshots.

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

docs/edge/en/enterprise/features/merged-step-card.mdx

@@ -0,0 +1,87 @@
+---
+title: One Card per Step
+description: "Each step on the Studio canvas is a single card that combines the task and the agent that performs it."
+icon: "layer-group"
+mode: "wide"
+---
+
+{/* CLEANUP: This <Note> banner is the only time-bound content on the page. After the feature ships (Wednesday, June 24th 2026), delete the banner below — the rest of the page is evergreen present-tense docs and needs no other edits. */}
+<Note>
+  **Rolling out Wednesday, June 24th.** The Studio canvas is moving to one card per step instead of separate task and agent nodes, to streamline the canvas as we add new functionality soon. Your existing automations keep working with no changes needed — every task and agent setting is still available, just organized onto a single card.
+</Note>
+
+## Overview
+
+On the Studio canvas, each step of work is represented by a **single card**. The card combines two things that used to live in separate nodes:
+
+- **The task** — what to do (name, description, expected output, and response format).
+- **The agent** — who does it (the assigned agent, its model, and its tools).
+
+An agent isn't an independent participant in your workflow — it's an attribute of the task: *which agent performs this work.* Putting the task and its agent on one card makes that relationship explicit and turns your automation into a single, left-to-right chain of work units that's easier to read at a glance.
+
+<Frame caption="One card per step: the task with its assigned agent summarized in the footer.">
+  ![Merged step cards on the canvas](/images/enterprise/merged-step-card-canvas.png)
+</Frame>
+
+## On the canvas
+
+Each collapsed card shows:
+
+- The **task name and description** at the top.
+- A **footer summarizing the assigned agent** — avatar, name, model, and tools.
+
+There's no separate agent node and no vertical agent → task edge. Your steps connect directly to one another in the order they run.
+
+## In the editor
+
+Open a card to edit it. The expanded view is the same card in a detailed state — not a different screen — organized into two clearly labeled sections.
+
+<Frame caption="The expanded editor: the task section open, the agent summarized below it.">
+  ![Expanded step editor](/images/enterprise/merged-step-card-editor.png)
+</Frame>
+
+### The task — what to do
+
+Open by default, since this is what you usually edit:
+
+- **Name**
+- **Description**
+- **Expected Output**
+- **Response Format** — surfaced here because it controls exactly what downstream steps (such as routing) read from this step.
+
+### The agent — who does it
+
+The assigned agent is shown as a summary — **name, model, and tools inline**. Its deeper configuration is preserved behind two disclosures:
+
+- **Role, goal & backstory**
+- **Agent settings** — reasoning, max reasoning attempts, allow delegation, max iterations, and LLM settings.
+
+<Tip>
+  An agent's full configuration — Role, Goal, Backstory, Model, Tools, LLM Settings, and the complete Agent Settings block — lives behind the **Role, goal & backstory** and **Agent settings** disclosures, organized by how often you edit it.
+</Tip>
+
+## Swapping vs. editing the agent
+
+There are two distinct ways to work with the agent on a card, and they do different things:
+
+- **Swap** reassigns *which* agent performs this task. Use the **Swap** control to pick a different agent from this project, choose one from your Agent Repository, or create a new agent. This is scoped to the task.
+- **Editing** the agent — opening **Role, goal & backstory** or **Agent settings** — changes the agent *itself*.
+
+<Frame caption="Swap changes which agent performs the task.">
+  ![Swap agent panel](/images/enterprise/merged-step-card-swap-agent.png)
+</Frame>
+
+<Warning>
+  **Agents are reusable and shared.** The same agent can perform more than one task across your project. Editing an agent's role, backstory, or settings updates that agent **everywhere it's used** — not just on the card you opened. If you want a change to apply to only one step, **Swap** in a different agent instead of editing the shared one.
+</Warning>
+
+## Related
+
+<CardGroup cols={2}>
+  <Card title="Crew Studio" href="/en/enterprise/features/crew-studio" icon="pencil">
+    Build automations with AI assistance and a visual editor.
+  </Card>
+  <Card title="Agent Repositories" href="/en/enterprise/features/agent-repositories" icon="users">
+    Manage and reuse agents across your automations.
+  </Card>
+</CardGroup>