v2 phase 2: agent-runner — provider interface, poll loop, formatter

AgentProvider abstraction with Claude and Mock implementations.
Poll loop reads messages_in, formats by kind, queries provider,
writes results to messages_out. Concurrent polling pushes follow-up
messages into active queries.

- providers/types.ts: AgentProvider, AgentQuery, ProviderEvent
- providers/claude.ts: wraps Agent SDK with MessageStream, hooks,
  transcript archiving
- providers/mock.ts: canned responses with push() support
- providers/factory.ts: createProvider()
- formatter.ts: format by kind (chat/task/webhook/system), XML
  escaping, routing extraction
- poll-loop.ts: poll → format → query → write, concurrent polling
- mcp-tools.ts: MCP server with send_message tool
- index-v2.ts: new entry point (config from env, enters poll loop)
- 11 new tests, all 288 tests pass

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

container/agent-runner/src/formatter.ts

@@ -0,0 +1,126 @@
+import type { MessageInRow } from './db/messages-in.js';
+
+/**
+ * Routing context extracted from messages_in rows.
+ * Copied to messages_out by default so responses go back to the sender.
+ */
+export interface RoutingContext {
+  platformId: string | null;
+  channelType: string | null;
+  threadId: string | null;
+  inReplyTo: string | null;
+}
+
+/**
+ * Extract routing context from a batch of messages.
+ * Uses the first message's routing fields.
+ */
+export function extractRouting(messages: MessageInRow[]): RoutingContext {
+  const first = messages[0];
+  return {
+    platformId: first?.platform_id ?? null,
+    channelType: first?.channel_type ?? null,
+    threadId: first?.thread_id ?? null,
+    inReplyTo: first?.id ?? null,
+  };
+}
+
+/**
+ * Format a batch of messages_in rows into a prompt string.
+ * Strips routing fields — the agent never sees platform_id, channel_type, thread_id.
+ */
+export function formatMessages(messages: MessageInRow[]): string {
+  if (messages.length === 0) return '';
+
+  // Group by kind
+  const chatMessages = messages.filter((m) => m.kind === 'chat' || m.kind === 'chat-sdk');
+  const taskMessages = messages.filter((m) => m.kind === 'task');
+  const webhookMessages = messages.filter((m) => m.kind === 'webhook');
+  const systemMessages = messages.filter((m) => m.kind === 'system');
+
+  const parts: string[] = [];
+
+  if (chatMessages.length > 0) {
+    parts.push(formatChatMessages(chatMessages));
+  }
+  if (taskMessages.length > 0) {
+    parts.push(...taskMessages.map(formatTaskMessage));
+  }
+  if (webhookMessages.length > 0) {
+    parts.push(...webhookMessages.map(formatWebhookMessage));
+  }
+  if (systemMessages.length > 0) {
+    parts.push(...systemMessages.map(formatSystemMessage));
+  }
+
+  return parts.join('\n\n');
+}
+
+function formatChatMessages(messages: MessageInRow[]): string {
+  if (messages.length === 1) {
+    return formatSingleChat(messages[0]);
+  }
+
+  const lines = ['<messages>'];
+  for (const msg of messages) {
+    const content = parseContent(msg.content);
+    const sender = content.sender || content.author?.fullName || content.author?.userName || 'Unknown';
+    const time = formatTime(msg.timestamp);
+    const text = content.text || '';
+    lines.push(`<message sender="${escapeXml(sender)}" time="${time}">${escapeXml(text)}</message>`);
+  }
+  lines.push('</messages>');
+  return lines.join('\n');
+}
+
+function formatSingleChat(msg: MessageInRow): string {
+  const content = parseContent(msg.content);
+  const sender = content.sender || content.author?.fullName || content.author?.userName || 'Unknown';
+  const time = formatTime(msg.timestamp);
+  const text = content.text || '';
+  return `<message sender="${escapeXml(sender)}" time="${time}">${escapeXml(text)}</message>`;
+}
+
+function formatTaskMessage(msg: MessageInRow): string {
+  const content = parseContent(msg.content);
+  const parts = ['[SCHEDULED TASK]'];
+  if (content.scriptOutput) {
+    parts.push('', 'Script output:', JSON.stringify(content.scriptOutput, null, 2));
+  }
+  parts.push('', 'Instructions:', content.prompt || '');
+  return parts.join('\n');
+}
+
+function formatWebhookMessage(msg: MessageInRow): string {
+  const content = parseContent(msg.content);
+  const source = content.source || 'unknown';
+  const event = content.event || 'unknown';
+  return `[WEBHOOK: ${source}/${event}]\n\n${JSON.stringify(content.payload || content, null, 2)}`;
+}
+
+function formatSystemMessage(msg: MessageInRow): string {
+  const content = parseContent(msg.content);
+  return `[SYSTEM RESPONSE]\n\nAction: ${content.action || 'unknown'}\nStatus: ${content.status || 'unknown'}\nResult: ${JSON.stringify(content.result || null)}`;
+}
+
+// eslint-disable-next-line @typescript-eslint/no-explicit-any
+function parseContent(json: string): any {
+  try {
+    return JSON.parse(json);
+  } catch {
+    return { text: json };
+  }
+}
+
+function formatTime(timestamp: string): string {
+  try {
+    const d = new Date(timestamp);
+    return `${d.getHours().toString().padStart(2, '0')}:${d.getMinutes().toString().padStart(2, '0')}`;
+  } catch {
+    return timestamp;
+  }
+}
+
+function escapeXml(str: string): string {
+  return str.replace(/&/g, '&amp;').replace(/</g, '&lt;').replace(/>/g, '&gt;').replace(/"/g, '&quot;');
+}