tui: batch SDK events to reduce render churn and improve responsiveness

Intelligently queue events and flush them in 16ms batches. Events processed within 16ms of the last flush are batched together to reduce the number of store updates and re-renders, preventing jank when receiving rapid consecutive events. Events after a 16ms gap are processed immediately to avoid adding latency.

packages/opencode/src/cli/cmd/tui/context/sdk.tsx

@@ -1,7 +1,7 @@
 import { createOpencodeClient, type Event } from "@opencode-ai/sdk"
 import { createSimpleContext } from "./helper"
 import { createGlobalEmitter } from "@solid-primitives/event-bus"
-import { onCleanup } from "solid-js"
+import { batch, onCleanup } from "solid-js"
 
 export const { use: useSDK, provider: SDKProvider } = createSimpleContext({
   name: "SDK",
@@ -17,8 +17,42 @@ export const { use: useSDK, provider: SDKProvider } = createSimpleContext({
     }>()
 
     sdk.event.subscribe().then(async (events) => {
+      let queue: Event[] = []
+      let timer: Timer | undefined
+      let last = 0
+
+      const flush = () => {
+        if (queue.length === 0) return
+        const events = queue
+        queue = []
+        timer = undefined
+        last = Date.now()
+        // Batch all event emissions so all store updates result in a single render
+        batch(() => {
+          for (const event of events) {
+            emitter.emit(event.type, event)
+          }
+        })
+      }
+
       for await (const event of events.stream) {
-        emitter.emit(event.type, event)
+        queue.push(event)
+        const elapsed = Date.now() - last
+
+        if (timer) continue
+        // If we just flushed recently (within 16ms), batch this with future events
+        // Otherwise, process immediately to avoid latency
+        if (elapsed < 16) {
+          timer = setTimeout(flush, 16)
+          continue
+        }
+        flush()
+      }
+
+      // Flush any remaining events
+      if (timer) clearTimeout(timer)
+      if (queue.length > 0) {
+        flush()
       }
     })