fix: streaming flicker aggressive static promotion (#608)

Co-authored-by: Letta <noreply@letta.com>

src/cli/components/AssistantMessageRich.tsx

@@ -16,6 +16,7 @@ type AssistantLine = {
   id: string;
   text: string;
   phase: "streaming" | "finished";
+  isContinuation?: boolean;
 };
 
 /**
@@ -23,7 +24,7 @@ type AssistantLine = {
  * This is a direct port from the old letta-code codebase to preserve the exact styling
  *
  * Features:
- * - Left column (2 chars wide) with bullet point marker
+ * - Left column (2 chars wide) with bullet point marker (unless continuation)
  * - Right column with wrapped text content
  * - Proper text normalization
  * - Support for markdown rendering (when MarkdownDisplay is available)
@@ -37,7 +38,7 @@ export const AssistantMessage = memo(({ line }: { line: AssistantLine }) => {
   return (
     <Box flexDirection="row">
       <Box width={2} flexShrink={0}>
-        <Text>●</Text>
+        <Text>{line.isContinuation ? " " : "●"}</Text>
       </Box>
       <Box flexGrow={1} width={contentWidth}>
         <MarkdownDisplay text={normalizedText} hangingIndent={0} />

src/cli/components/ReasoningMessageRich.tsx

@@ -16,6 +16,7 @@ type ReasoningLine = {
   id: string;
   text: string;
   phase: "streaming" | "finished";
+  isContinuation?: boolean;
 };
 
 /**
@@ -23,7 +24,7 @@ type ReasoningLine = {
  * This is a direct port from the old letta-code codebase to preserve the exact styling
  *
  * Features:
- * - Header row with "✻" symbol and "Thinking…" text
+ * - Header row with "✻" symbol and "Thinking…" text (unless continuation)
  * - Reasoning content indented with 2 spaces
  * - Full markdown rendering with dimmed colors
  * - Proper text normalization
@@ -34,6 +35,20 @@ export const ReasoningMessage = memo(({ line }: { line: ReasoningLine }) => {
 
   const normalizedText = normalize(line.text);
 
+  // Continuation lines skip the header, just show content
+  if (line.isContinuation) {
+    return (
+      <Box flexDirection="row">
+        <Box width={2} flexShrink={0}>
+          <Text> </Text>
+        </Box>
+        <Box flexGrow={1} width={contentWidth}>
+          <MarkdownDisplay text={normalizedText} dimColor={true} />
+        </Box>
+      </Box>
+    );
+  }
+
   return (
     <Box flexDirection="column">
       <Box flexDirection="row">