perf(tui): tighten markdown demo rendering

packages/opencode/src/cli/cmd/run/runtime.ts

@@ -14,7 +14,7 @@
 //   4. runs the prompt queue until the footer closes.
 import { createOpencodeClient } from "@opencode-ai/sdk/v2"
 import { Flag } from "@opencode-ai/core/flag/flag"
-import { createRunDemo } from "./demo"
+import type { createRunDemo } from "./demo"
 import { resolveDiffStyle, resolveFooterKeybinds, resolveModelInfo, resolveSessionInfo } from "./runtime.boot"
 import { createRuntimeLifecycle } from "./runtime.lifecycle"
 import { recordRunSpanError, setRunSpanAttributes, withRunSpan } from "./otel"
@@ -135,6 +135,10 @@ function variantsFor(providers: RunProvider[], model: RunInput["model"]) {
   return Object.keys(providers.find((item) => item.id === model.providerID)?.models?.[model.modelID]?.variants ?? {})
 }
 
+async function createDemo(input: Parameters<typeof createRunDemo>[0]) {
+  return (await import("./demo")).createRunDemo(input)
+}
+
 async function resolveExitTitle(
   ctx: BootContext,
   input: RunRuntimeInput,
@@ -425,7 +429,7 @@ async function runInteractiveRuntime(input: RunRuntimeInput): Promise<void> {
 
       if (input.demo) {
         await ensureSession()
-        state.demo = createRunDemo({
+        state.demo = await createDemo({
           footer,
           sessionID: state.sessionID,
           thinking: input.thinking,
@@ -548,7 +552,7 @@ async function runInteractiveRuntime(input: RunRuntimeInput): Promise<void> {
                   state.history = []
                   includeFiles = true
                   state.demo = input.demo
-                    ? createRunDemo({
+                    ? await createDemo({
                         footer,
                         sessionID: state.sessionID,
                         thinking: input.thinking,

packages/opencode/src/cli/cmd/tui/routes/session/index.tsx

@@ -1573,8 +1573,14 @@ function TextPart(props: { last: boolean; part: TextPart; message: AssistantMess
     let spaces = 0
     let replaced = false
     let skipWhitespace = false
-    return chunks.map((chunk) => {
+    return chunks.flatMap((chunk) => {
+      const result: TextChunk[] = []
       let next = ""
+      const flush = () => {
+        if (!next) return
+        result.push(next === chunk.text ? chunk : { ...chunk, text: next })
+        next = ""
+      }
       for (const char of chunk.text) {
         if (skipWhitespace && (char === " " || char === "\t")) {
           skipWhitespace = false
@@ -1587,7 +1593,8 @@ function TextPart(props: { last: boolean; part: TextPart; message: AssistantMess
           continue
         }
         if (lineStart && !replaced && char === ">") {
-          next += "│ "
+          flush()
+          result.push({ __isChunk: true, text: "│ ", fg: theme.textMuted, attributes: TextAttributes.NONE })
           replaced = true
           skipWhitespace = true
           continue
@@ -1602,7 +1609,8 @@ function TextPart(props: { last: boolean; part: TextPart; message: AssistantMess
         }
         lineStart = false
       }
-      return next === chunk.text ? chunk : { ...chunk, text: next }
+      flush()
+      return result
     })
   }
   const trimCodeIndent = (value: string) => {

packages/opencode/src/cli/cmd/tui/thread.ts

@@ -142,6 +142,7 @@ export const TuiThreadCommand = cmd({
       }
       const cwd = Filesystem.resolve(process.cwd())
       const config = TuiConfig.get()
+      config.catch(() => {})
 
       if (args.demo) {
         const { createTuiDemo } = await import("./demo")