fix: clean up progress tracking, fix subagent summary field handling

- Use system/task_progress subtype (not top-level type) for subagent events
- Extract intermediate assistant text between tool calls as progress
- Only show SDK-generated summaries for subagent progress (skip noisy per-tool updates)
- Truncate progress messages to Discord 2000 char limit
- Remove verbose debug logging from production

src/agent-runner.ts

@@ -238,7 +238,7 @@ export async function runAgentProcess(
       const lines = chunk.trim().split('\n');
       for (const line of lines) {
         if (!line) continue;
-        if (line.includes('Turn in progress')) {
+        if (line.includes('Turn in progress') || line.includes('Subagent') || line.includes('Intermediate assistant')) {
           logger.info(
             { group: group.name, chatJid: input.chatJid, runId: input.runId },
             line.replace(/^\[.*?\]\s*/, ''),