[taskboard] add dispatch control plane

lib/db.ts

@@ -7,6 +7,41 @@ const DB_PATH = process.env.DB_PATH || path.join(process.cwd(), "data", "tasks.d
 fs.mkdirSync(path.dirname(DB_PATH), { recursive: true });
 
 let database: sqlite3.Database | null = null;
+let databaseReady: Promise<void> | null = null;
+
+function getColumnNames(db: sqlite3.Database, tableName: string) {
+  return new Promise<string[]>((resolve, reject) => {
+    db.all<{ name: string }>(`PRAGMA table_info(${tableName})`, [], (error, rows) => {
+      if (error) {
+        reject(error);
+        return;
+      }
+      resolve(rows.map((row) => row.name));
+    });
+  });
+}
+
+async function ensureColumn(
+  db: sqlite3.Database,
+  tableName: string,
+  columnName: string,
+  definition: string,
+) {
+  const columnNames = await getColumnNames(db, tableName);
+  if (columnNames.includes(columnName)) {
+    return;
+  }
+
+  await new Promise<void>((resolve, reject) => {
+    db.run(`ALTER TABLE ${tableName} ADD COLUMN ${columnName} ${definition}`, (error) => {
+      if (error) {
+        reject(error);
+        return;
+      }
+      resolve();
+    });
+  });
+}
 
 function getDatabase() {
   if (database) {
@@ -41,12 +76,63 @@ function getDatabase() {
         timestamp TEXT NOT NULL DEFAULT (datetime('now'))
       )
     `);
+    database?.run(`
+      CREATE TABLE IF NOT EXISTS task_events (
+        id INTEGER PRIMARY KEY AUTOINCREMENT,
+        task_id INTEGER NOT NULL,
+        assignee TEXT NOT NULL DEFAULT '',
+        family TEXT,
+        host TEXT NOT NULL DEFAULT '',
+        event_type TEXT NOT NULL,
+        state TEXT,
+        summary TEXT NOT NULL,
+        detail TEXT NOT NULL DEFAULT '',
+        created_at TEXT NOT NULL DEFAULT (datetime('now'))
+      )
+    `);
+    database?.run(`
+      CREATE INDEX IF NOT EXISTS idx_task_events_task_time
+      ON task_events(task_id, created_at DESC)
+    `);
+    database?.run(`
+      CREATE INDEX IF NOT EXISTS idx_task_events_assignee_time
+      ON task_events(assignee, created_at DESC)
+    `);
   });
 
+  databaseReady = (async () => {
+    if (!database) {
+      return;
+    }
+
+    await ensureColumn(database, "tasks", "family", "TEXT");
+    await ensureColumn(database, "tasks", "target_host", "TEXT NOT NULL DEFAULT ''");
+    await ensureColumn(database, "tasks", "target_channel", "TEXT NOT NULL DEFAULT ''");
+    await ensureColumn(database, "tasks", "dispatch_method", "TEXT NOT NULL DEFAULT 'manual'");
+    await ensureColumn(database, "tasks", "dispatch_state", "TEXT NOT NULL DEFAULT 'planned'");
+    await ensureColumn(database, "tasks", "template_key", "TEXT");
+    await ensureColumn(database, "tasks", "repo_slug", "TEXT");
+    await ensureColumn(database, "tasks", "base_branch", "TEXT");
+    await ensureColumn(database, "tasks", "preferred_agent", "TEXT");
+    await ensureColumn(database, "tasks", "reasoning_effort", "TEXT");
+    await ensureColumn(database, "tasks", "model_hint", "TEXT");
+    await ensureColumn(database, "tasks", "last_dispatch_at", "TEXT");
+    await ensureColumn(database, "tasks", "acknowledged_at", "TEXT");
+    await ensureColumn(database, "tasks", "last_error", "TEXT");
+  })();
+
   return database;
 }
 
-export function all<T>(sql: string, params: unknown[] = []) {
+async function ensureReady() {
+  getDatabase();
+  if (databaseReady) {
+    await databaseReady;
+  }
+}
+
+export async function all<T>(sql: string, params: unknown[] = []) {
+  await ensureReady();
   const db = getDatabase();
   return new Promise<T[]>((resolve, reject) => {
     db.all(sql, params, (error, rows) => {
@@ -59,7 +145,8 @@ export function all<T>(sql: string, params: unknown[] = []) {
   });
 }
 
-export function get<T>(sql: string, params: unknown[] = []) {
+export async function get<T>(sql: string, params: unknown[] = []) {
+  await ensureReady();
   const db = getDatabase();
   return new Promise<T | undefined>((resolve, reject) => {
     db.get(sql, params, (error, row) => {
@@ -72,7 +159,8 @@ export function get<T>(sql: string, params: unknown[] = []) {
   });
 }
 
-export function run(sql: string, params: unknown[] = []) {
+export async function run(sql: string, params: unknown[] = []) {
+  await ensureReady();
   const db = getDatabase();
   return new Promise<{ lastID: number; changes: number }>((resolve, reject) => {
     db.run(sql, params, function onRun(error) {