fix: pass assistantName to container agent instead of hardcoding 'Andy'

The container agent-runner had 'Andy' hardcoded as the sender name in
archived conversation transcripts. This ignored the configurable
ASSISTANT_NAME setting, so users who changed their assistant's name
(via .env or config) would still see 'Andy' in transcripts.

- Add assistantName field to ContainerInput interface (both host and
  container copies)
- Pass ASSISTANT_NAME from config through to container in index.ts
  and task-scheduler.ts
- Thread assistantName through createPreCompactHook and
  formatTranscriptMarkdown in the agent-runner
- Use 'AssistantNameMissing' as fallback instead of 'Andy' so a
  missing name is visible rather than silently wrong

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

src/task-scheduler.ts

@@ -4,6 +4,7 @@ import fs from 'fs';
 import path from 'path';
 
 import {
+  ASSISTANT_NAME,
   GROUPS_DIR,
   IDLE_TIMEOUT,
   MAIN_GROUP_FOLDER,
@@ -113,6 +114,7 @@ async function runTask(
         chatJid: task.chat_jid,
         isMain,
         isScheduledTask: true,
+        assistantName: ASSISTANT_NAME,
       },
       (proc, containerName) => deps.onProcess(task.chat_jid, proc, containerName, task.group_folder),
       async (streamedOutput: ContainerOutput) => {