v2 phase 1: foundation — types, DB layer, logging

Add the v2 data layer: typed interfaces, central DB with migration
runner, per-entity CRUD, and agent-runner session DB operations.

- src/log.ts: concise message-first logging API
- src/types-v2.ts: AgentGroup, MessagingGroup, Session, MessageIn/Out
- src/db/: connection (WAL), migration runner, 001-initial schema,
  CRUD for agent_groups, messaging_groups, sessions, pending_questions
- container/agent-runner/src/db/: session DB connection, messages_in
  reads + status transitions, messages_out writes
- 31 new tests, all 277 tests pass

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

src/db/schema.ts

@@ -0,0 +1,103 @@
+/**
+ * Reference copy of the current v2 schema.
+ * Read this to understand the DB structure.
+ * Actual creation is done by migrations — do not use this at runtime.
+ */
+
+export const SCHEMA = `
+-- Agent workspaces: folder, skills, CLAUDE.md, container config
+CREATE TABLE agent_groups (
+  id               TEXT PRIMARY KEY,
+  name             TEXT NOT NULL,
+  folder           TEXT NOT NULL UNIQUE,
+  is_admin         INTEGER DEFAULT 0,
+  agent_provider   TEXT,
+  container_config TEXT,
+  created_at       TEXT NOT NULL
+);
+
+-- Platform groups/channels
+CREATE TABLE messaging_groups (
+  id               TEXT PRIMARY KEY,
+  channel_type     TEXT NOT NULL,
+  platform_id      TEXT NOT NULL,
+  name             TEXT,
+  is_group         INTEGER DEFAULT 0,
+  admin_user_id    TEXT,
+  created_at       TEXT NOT NULL,
+  UNIQUE(channel_type, platform_id)
+);
+
+-- Which agent groups handle which messaging groups
+CREATE TABLE messaging_group_agents (
+  id                 TEXT PRIMARY KEY,
+  messaging_group_id TEXT NOT NULL REFERENCES messaging_groups(id),
+  agent_group_id     TEXT NOT NULL REFERENCES agent_groups(id),
+  trigger_rules      TEXT,
+  response_scope     TEXT DEFAULT 'all',
+  session_mode       TEXT DEFAULT 'shared',
+  priority           INTEGER DEFAULT 0,
+  created_at         TEXT NOT NULL,
+  UNIQUE(messaging_group_id, agent_group_id)
+);
+
+-- Sessions: one folder = one session = one container when running
+CREATE TABLE sessions (
+  id                 TEXT PRIMARY KEY,
+  agent_group_id     TEXT NOT NULL REFERENCES agent_groups(id),
+  messaging_group_id TEXT REFERENCES messaging_groups(id),
+  thread_id          TEXT,
+  agent_provider     TEXT,
+  status             TEXT DEFAULT 'active',
+  container_status   TEXT DEFAULT 'stopped',
+  last_active        TEXT,
+  created_at         TEXT NOT NULL
+);
+CREATE INDEX idx_sessions_agent_group ON sessions(agent_group_id);
+CREATE INDEX idx_sessions_lookup ON sessions(messaging_group_id, thread_id);
+
+-- Pending interactive questions
+CREATE TABLE pending_questions (
+  question_id    TEXT PRIMARY KEY,
+  session_id     TEXT NOT NULL REFERENCES sessions(id),
+  message_out_id TEXT NOT NULL,
+  platform_id    TEXT,
+  channel_type   TEXT,
+  thread_id      TEXT,
+  created_at     TEXT NOT NULL
+);
+`;
+
+/**
+ * Session DB schema — created fresh by the host for each session.
+ */
+export const SESSION_SCHEMA = `
+CREATE TABLE messages_in (
+  id             TEXT PRIMARY KEY,
+  kind           TEXT NOT NULL,
+  timestamp      TEXT NOT NULL,
+  status         TEXT DEFAULT 'pending',
+  status_changed TEXT,
+  process_after  TEXT,
+  recurrence     TEXT,
+  tries          INTEGER DEFAULT 0,
+  platform_id    TEXT,
+  channel_type   TEXT,
+  thread_id      TEXT,
+  content        TEXT NOT NULL
+);
+
+CREATE TABLE messages_out (
+  id             TEXT PRIMARY KEY,
+  in_reply_to    TEXT,
+  timestamp      TEXT NOT NULL,
+  delivered      INTEGER DEFAULT 0,
+  deliver_after  TEXT,
+  recurrence     TEXT,
+  kind           TEXT NOT NULL,
+  platform_id    TEXT,
+  channel_type   TEXT,
+  thread_id      TEXT,
+  content        TEXT NOT NULL
+);
+`;