Parse JSONL events in ui-parser for cleaner output

Skip step_start/step_finish/tool_use events in UI display, extract
text from type:text events. Provides cleaner real-time output.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/ui-parser.ts

@@ -9,5 +9,26 @@ type TranscriptEntry =
   | { kind: "system"; ts: string; text: string };
 
 export function parseStdoutLine(line: string, ts: string): TranscriptEntry[] {
-  return [{ kind: "stdout", ts, text: line }];
+  const trimmed = line.trim();
+  if (!trimmed) return [];
+
+  // Try to parse as JSONL event from opencode run --format json
+  try {
+    const event = JSON.parse(trimmed);
+    const type = typeof event.type === "string" ? event.type : "";
+    const part = typeof event.part === "object" && event.part !== null ? event.part : {};
+
+    if (type === "text" && typeof part.text === "string" && part.text.trim()) {
+      return [{ kind: "stdout", ts, text: part.text.trim() }];
+    }
+
+    // Skip non-display event types
+    if (type === "step_start" || type === "step_finish" || type === "tool_use") {
+      return [];
+    }
+  } catch {
+    // Not JSON — treat as raw stdout
+  }
+
+  return [{ kind: "stdout", ts, text: trimmed }];
 }