docs(ai-transport): add roadmap page

Add a customer-facing AI Transport roadmap page covering three horizons
(Now, Next, Future) as capability tables, with a pointer to contact Ably
to influence direction. Link Now capabilities to their feature pages.

Add a Roadmap entry to the AI Transport navigation.

Author: rainbowFi

src/data/nav/aitransport.ts

@@ -320,6 +320,16 @@ export default {
         },
       ],
     },
+    {
+      name: 'Roadmap',
+      pages: [
+        {
+          name: 'Roadmap',
+          link: '/docs/ai-transport/roadmap',
+          index: true,
+        },
+      ],
+    },
   ],
   api: [],
 } satisfies NavProduct;

src/pages/docs/ai-transport/roadmap.mdx

@@ -0,0 +1,52 @@
+---
+title: "AI Transport roadmap"
+meta_description: "The AI Transport roadmap across three horizons: capabilities available now, capabilities in active development, and capabilities planned for the future."
+meta_keywords: "AI Transport, roadmap, durable sessions, AI infrastructure, token streaming, human handover, durable execution"
+intro: "AI Transport is under active development with new releases shipping regularly. What features can you expect to see next?"
+---
+
+This page shows where AI Transport is heading. The roadmap is dynamic and updated based on the feedback received from customers. The fastest way to influence this roadmap is to [contact Ably](https://ably.com/contact), explaining what you are trying to build and where AI Transport can help you.
+
+## Now <a id="now"/>
+
+Available today.
+
+| Capability | Description |
+| --- | --- |
+| [Resumable token streaming](/docs/ai-transport/features/token-streaming) | Tokens stream over a session rather than a single HTTP request, so a dropped connection resumes mid-response with nothing lost or duplicated, and a reconnecting client catches up automatically. |
+| [Connection resilience](/docs/ai-transport/features/reconnection-and-recovery) | Realtime delivery over WebSocket with automatic fallback to HTTP streaming and long-polling, so streams survive proxies, firewalls, and unreliable networks. |
+| [Multi-device session continuity](/docs/ai-transport/features/multi-device) | The same session opens on any device the user picks up, with the full conversation and current state. |
+| [Persistent history and replay](/docs/ai-transport/features/history) | Conversations survive disconnects and stay available as history, for resumption, audit, and review. |
+| Bidirectional control | Any client signals the agent through the session, so a user can [cancel generation](/docs/ai-transport/features/cancellation), [interrupt](/docs/ai-transport/features/interruption), [send again while the agent responds](/docs/ai-transport/features/double-texting), and keep interacting rather than only consuming a one-way stream. |
+| [Conversation branching](/docs/ai-transport/features/branching) | Edit and regenerate messages, with each branch kept in the session tree. |
+| Client-side tool calls and approval gates | Call [client tools](/docs/ai-transport/features/tool-calling) over the session, with [human-in-the-loop](/docs/ai-transport/features/human-in-the-loop) approval where you need it. |
+| Drop-in framework integration | A drop-in transport for the [Vercel AI SDK](/docs/ai-transport/getting-started/vercel-ai-sdk), plus the [Core SDK](/docs/ai-transport/getting-started/core-sdk) for everything else. |
+| Shared live state and presence | [Agent presence](/docs/ai-transport/features/agent-presence) and [shared session state](/docs/ai-transport/features/liveobjects) exposed directly through the SDK. |
+| Enterprise-ready platform | SOC 2 Type II and HIPAA, on Ably's realtime [infrastructure](/docs/ai-transport/concepts/infrastructure). |
+
+## Next <a id="next"/>
+
+Actively building.
+
+| Capability | Description |
+| --- | --- |
+| Durable execution support | Pair durable sessions with Temporal and Vercel WDK, so the workflow and the user experience are both crash-proof. |
+| Human and AI handover | Transfer a conversation between an AI and a human agent and back again using the AIT SDK, with live supervision and escalation. |
+| Mid-session steering | Redirect or steer the agent while it responds. |
+| Push notifications through the SDK | Reach users when they are away, including iOS Live Activities for long-running tasks. |
+| More provider codecs | Native integrations for OpenAI and Anthropic, so more of the ecosystem is a drop-in. |
+| More language SDKs | AI Transport SDK implementation in Python. |
+| Ably Chat integration | A clean path from chat use cases into AI Transport. |
+
+## Future <a id="future"/>
+
+Planned and exploring.
+
+| Capability | Description |
+| --- | --- |
+| More language SDKs | Java, Swift, Kotlin, and .NET. |
+| More framework integrations | LangChain and LangGraph, TanStack AI, AG-UI, Vue, and Svelte. |
+| More model-specific codecs | Gemini. |
+| Sub-agent orchestration | Better primitives for coordinating multiple sub-agents in a single Run. |
+| More durable-execution integrations | Inngest and trigger.dev. |
+| Multimodal | Audio and video delivery, and integrations with voice providers. |