chore: 还原 PR #44 手写实现，准备由 Codex 按新规则重写

db/schema.sql

@@ -524,7 +524,6 @@ CREATE TABLE IF NOT EXISTS tasks (
     timeout_seconds INTEGER NOT NULL DEFAULT 0,
     plan_heartbeat_seconds INTEGER NOT NULL DEFAULT 300,
     coverage_enabled BOOLEAN NOT NULL DEFAULT true,
-    worker_count   INTEGER NOT NULL DEFAULT 0, -- 0=用全局默认 workers
     pinned_at      TIMESTAMPTZ,
     first_run_at   TIMESTAMPTZ,
     deadline_at    TIMESTAMPTZ,
@@ -547,8 +546,6 @@ ALTER TABLE tasks ADD COLUMN IF NOT EXISTS queued BOOLEAN NOT NULL DEFAULT false
 -- 给 agent 开放 add_task_scope/list_untested_assets;false=全部关闭(见 task_scope.go)。
 -- 存量任务默认 true 保持原行为;company 关联(task_scope kind=company)不受此开关影响。
 ALTER TABLE tasks ADD COLUMN IF NOT EXISTS coverage_enabled BOOLEAN NOT NULL DEFAULT true;
--- 任务级 Worker 运行数量;0=用全局默认(settings.workers)。补旧库。
-ALTER TABLE tasks ADD COLUMN IF NOT EXISTS worker_count INTEGER NOT NULL DEFAULT 0;
 -- queued_at makes admission FIFO reflect the actual enqueue order rather than the
 -- task creation order. queue_mode distinguishes first bootstrap from resuming an
 -- exploration that already owns goals/history.
@@ -620,21 +617,16 @@ CREATE TABLE IF NOT EXISTS task_templates (
     nkey        TEXT NOT NULL UNIQUE,
     description TEXT NOT NULL,
     goal        TEXT NOT NULL,
-    remark      TEXT NOT NULL DEFAULT '',
     -- 预设的任务分类；分类删除时置空（与 tasks.category_id 一致，不阻断）。
     category_id     BIGINT REFERENCES task_categories(id) ON DELETE SET NULL,
     -- 预设的任务级拦截/允许规则快照(AssetInterceptRuleInput 数组)；应用模板时灌进新任务。
     intercept_rules JSONB NOT NULL DEFAULT '[]',
-    -- 预设的任务级 Worker 运行数量;0=用全局默认。
-    worker_count INTEGER NOT NULL DEFAULT 0,
     created_at  TIMESTAMPTZ NOT NULL DEFAULT now(),
     updated_at  TIMESTAMPTZ NOT NULL DEFAULT now()
 );
 -- 补旧库(已发版,加列带 IF NOT EXISTS)。
 ALTER TABLE task_templates ADD COLUMN IF NOT EXISTS category_id BIGINT REFERENCES task_categories(id) ON DELETE SET NULL;
 ALTER TABLE task_templates ADD COLUMN IF NOT EXISTS intercept_rules JSONB NOT NULL DEFAULT '[]';
-ALTER TABLE task_templates ADD COLUMN IF NOT EXISTS remark TEXT NOT NULL DEFAULT '';
-ALTER TABLE task_templates ADD COLUMN IF NOT EXISTS worker_count INTEGER NOT NULL DEFAULT 0;
 CREATE INDEX IF NOT EXISTS idx_task_templates_updated ON task_templates(updated_at DESC, id DESC);
 DROP TRIGGER IF EXISTS trg_task_templates_upd ON task_templates;
 CREATE TRIGGER trg_task_templates_upd BEFORE UPDATE ON task_templates