docs: add Next Steps roadmap (Phases A-C) to integration spec

BITSTREAM_INTEGRATION.md

@@ -894,3 +894,58 @@ The relay uses `tokio-tungstenite` and routes:
 6. **No `Serialize`/`Deserialize` on AST**: The AST types don't derive serde traits. `SignalManifest` should derive `Serialize` if you want to embed it as JSON in the compiled output.
 
 7. **`ds-cli` doesn't depend on `ds-stream`**: The CLI can't import relay code directly. To auto-start the relay, use `std::process::Command::new("cargo").args(["run", "-p", "ds-stream"])`.
+
+---
+
+## 🚀 Next Steps
+
+All spec changes are implemented. The pipeline is wired end-to-end. Here's the roadmap for what comes next:
+
+### Phase A: Prove It Works (High Priority)
+
+#### 1. End-to-End Integration Test
+Write a `.ds` file with `stream main on "ws://..."`, run the relay + `dreamstack dev`, open two browser tabs, and verify signal changes propagate in real time. This is the first time compiler-generated streaming code talks to the Rust relay.
+
+```bash
+# Terminal 1: start relay
+cargo run -p ds-stream
+
+# Terminal 2: compile and serve
+dreamstack stream examples/counter.ds
+
+# Open http://localhost:3000 — click buttons, verify signals stream to relay
+# Open stream-receiver.html — verify it receives updates
+```
+
+#### 2. Receiver `.ds` Syntax Demo
+Create a `receiver.ds` that uses `stream from "ws://localhost:9100"` to consume a remote stream and render it locally — closing the compiler-to-compiler loop.
+
+```
+let remote = stream from "ws://localhost:9100"
+
+view main = column [
+  text "Remote count: {remote.count}"
+  text "Remote doubled: {remote.doubled}"
+]
+```
+
+### Phase B: Infrastructure
+
+#### 3. WASM Codec
+Compile `ds-stream` codec to WebAssembly so browsers share the exact same `rle_encode`/`rle_decode` as the Rust relay. Eliminates protocol drift risk from duplicated JS implementations.
+
+#### 4. Multi-Source Routing
+Support `/source/{view_name}` on the relay so multiple views can stream independently through the same relay instance.
+
+#### 5. WebRTC Transport
+Add WebRTC as a transport option alongside WebSocket for sub-frame latency. WebSocket adds ~1-2 frames of buffering; WebRTC data channels can eliminate this.
+
+### Phase C: Polish
+
+#### 6. Language Documentation
+Add a streaming section to `DREAMSTACK.md` covering the `stream` keyword, `stream from` expression, and streaming modes.
+
+#### 7. Example `.ds` Files
+Create compiler-native streaming examples:
+- `examples/streaming-counter.ds` — basic signal streaming
+- `examples/streaming-physics.ds` — scene state streaming with physics bodies