refactor(contracts,agent): single capability spec and agent run event definitions in contracts

B3: CapabilityDescriptor gains replay; CapabilitySpec + capabilitySpec(id) assemble
CAPABILITY_CATALOG + CAPABILITY_IO; drop CapabilityDefinition/CapabilityRisk. agent
registry registers contracts CapabilitySpec (kind/allowedKinds instead of its own
scope enum; approve also requires authorize). AgentRun port renamed AgentRunHandle.

B9: contracts AgentRunEvent/AgentRunEventBody/AgentRunEventRow/AgentUsageTotals with
row and SSE mapping helpers; agent onEvent receives AgentRunEvent, delivered serially
in seq order, firstSeq continues numbering across processes.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

packages/tasks/src/migrate.ts

@@ -1,25 +0,0 @@
-import { promises as fs } from "node:fs";
-import path from "node:path";
-import { fileURLToPath } from "node:url";
-import { type Kysely, sql } from "kysely";
-import { FileMigrationProvider, type MigrationResultSet, Migrator } from "kysely/migration";
-
-/** 本包自带迁移(tasks_run_meta / tasks_fact / tasks_op_ledger),W2 合并进 packages/db */
-export const TASKS_MIGRATIONS_DIR = fileURLToPath(new URL("../migrations", import.meta.url));
-
-/** 迁移到最新;表建在连接的默认 schema(search_path)里,迁移记录表独立命名避免与 @umt/db 冲突 */
-// biome-ignore lint/suspicious/noExplicitAny: 迁移器不关心具体表类型
-export async function migrateTasksTables(db: Kysely<any>): Promise<MigrationResultSet> {
-  // 显式指定迁移记录表的 schema:Kysely 默认按表名跨 schema 判断存在性,多个 schema 并存时会误判
-  const { rows } = await sql<{ schema: string }>`SELECT current_schema() AS schema`.execute(db);
-  const migrator = new Migrator({
-    db,
-    provider: new FileMigrationProvider({ fs, path, migrationFolder: TASKS_MIGRATIONS_DIR }),
-    migrationTableName: "tasks_migration",
-    migrationLockTableName: "tasks_migration_lock",
-    migrationTableSchema: rows[0]!.schema,
-  });
-  const result = await migrator.migrateToLatest();
-  if (result.error) throw result.error;
-  return result;
-}