v2 phase 4+5: Discord via Chat SDK, expanded MCP tools, message seq IDs

- Chat SDK bridge + Discord adapter (gateway listener, message routing)
- MCP tools refactored into modular structure: core (send_message, send_file,
  edit_message, add_reaction), scheduling (schedule/list/cancel/pause/resume
  tasks), interactive (ask_user_question, send_card), agents (send_to_agent)
- Message seq IDs: shared integer sequence across messages_in/out so agents
  see small numeric IDs instead of platform snowflakes
- busy_timeout=5000 for session DB (poll loop + MCP server concurrent access)
- Always copy agent-runner source to fix stale cache when non-index files change
- Seed script for Discord testing, e2e test script

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

container/agent-runner/src/db/connection.ts

@@ -8,6 +8,7 @@ export function getSessionDb(): Database.Database {
   if (!_db) {
     _db = new Database(process.env.SESSION_DB_PATH || SESSION_DB_PATH);
     _db.pragma('journal_mode = DELETE');
+    _db.pragma('busy_timeout = 5000');
     _db.pragma('foreign_keys = ON');
   }
   return _db;
@@ -20,6 +21,7 @@ export function initTestSessionDb(): Database.Database {
   _db.exec(`
     CREATE TABLE messages_in (
       id             TEXT PRIMARY KEY,
+      seq            INTEGER UNIQUE,
       kind           TEXT NOT NULL,
       timestamp      TEXT NOT NULL,
       status         TEXT DEFAULT 'pending',
@@ -34,6 +36,7 @@ export function initTestSessionDb(): Database.Database {
     );
     CREATE TABLE messages_out (
       id             TEXT PRIMARY KEY,
+      seq            INTEGER UNIQUE,
       in_reply_to    TEXT,
       timestamp      TEXT NOT NULL,
       delivered      INTEGER DEFAULT 0,

container/agent-runner/src/db/messages-in.ts

@@ -2,6 +2,7 @@ import { getSessionDb } from './connection.js';
 
 export interface MessageInRow {
   id: string;
+  seq: number | null;
   kind: string;
   timestamp: string;
   status: string;

container/agent-runner/src/db/messages-out.ts

@@ -2,6 +2,7 @@ import { getSessionDb } from './connection.js';
 
 export interface MessageOutRow {
   id: string;
+  seq: number | null;
   in_reply_to: string | null;
   timestamp: string;
   delivered: number;
@@ -26,22 +27,44 @@ export interface WriteMessageOut {
   content: string;
 }
 
-/** Write a new outbound message. */
-export function writeMessageOut(msg: WriteMessageOut): void {
-  getSessionDb()
-    .prepare(
-      `INSERT INTO messages_out (id, in_reply_to, timestamp, delivered, deliver_after, recurrence, kind, platform_id, channel_type, thread_id, content)
-       VALUES (@id, @in_reply_to, datetime('now'), 0, @deliver_after, @recurrence, @kind, @platform_id, @channel_type, @thread_id, @content)`,
-    )
-    .run({
-      in_reply_to: null,
-      deliver_after: null,
-      recurrence: null,
-      platform_id: null,
-      channel_type: null,
-      thread_id: null,
-      ...msg,
-    });
+/** Write a new outbound message, auto-assigning a seq number. */
+export function writeMessageOut(msg: WriteMessageOut): number {
+  const db = getSessionDb();
+  const nextSeq = (
+    db
+      .prepare(
+        `SELECT COALESCE(MAX(seq), 0) + 1 AS next FROM (
+           SELECT seq FROM messages_in WHERE seq IS NOT NULL
+           UNION ALL
+           SELECT seq FROM messages_out WHERE seq IS NOT NULL
+         )`,
+      )
+      .get() as { next: number }
+  ).next;
+
+  db.prepare(
+    `INSERT INTO messages_out (id, seq, in_reply_to, timestamp, delivered, deliver_after, recurrence, kind, platform_id, channel_type, thread_id, content)
+     VALUES (@id, @seq, @in_reply_to, datetime('now'), 0, @deliver_after, @recurrence, @kind, @platform_id, @channel_type, @thread_id, @content)`,
+  ).run({
+    in_reply_to: null,
+    deliver_after: null,
+    recurrence: null,
+    platform_id: null,
+    channel_type: null,
+    thread_id: null,
+    ...msg,
+    seq: nextSeq,
+  });
+
+  return nextSeq;
+}
+
+/** Look up a message's platform ID by seq number. */
+export function getMessageIdBySeq(seq: number): string | null {
+  const inRow = getSessionDb().prepare('SELECT id FROM messages_in WHERE seq = ?').get(seq) as { id: string } | undefined;
+  if (inRow) return inRow.id;
+  const outRow = getSessionDb().prepare('SELECT id FROM messages_out WHERE seq = ?').get(seq) as { id: string } | undefined;
+  return outRow?.id ?? null;
 }
 
 /** Get undelivered messages (for host polling). */