fix: 彻底移除 /loop 及 cron 工具的 feature('AGENT_TRIGGERS') gate

上次提交仅移除了 isKairosCronEnabled 中的 gate，但 /loop 整条链路
仍被 feature('AGENT_TRIGGERS') 拦截导致无法使用：
- skills/bundled/index.ts: registerLoopSkill() 未被调用
- tools.ts: CronCreate/Delete/List 工具未加载
- constants/tools.ts: cron 工具名未加入 teammate 工具列表
- screens/REPL.tsx: useScheduledTasks hook 被跳过
- cli/print.ts: pipe 模式 cron 调度器未初始化

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/screens/REPL.tsx

@@ -197,7 +197,7 @@ const PROACTIVE_NO_OP_SUBSCRIBE = (_cb: () => void) => () => {};
 const PROACTIVE_FALSE = () => false;
 const SUGGEST_BG_PR_NOOP = (_p: string, _n: string): boolean => false;
 const useProactive = feature('PROACTIVE') || feature('KAIROS') ? require('../proactive/useProactive.js').useProactive : null;
-const useScheduledTasks = feature('AGENT_TRIGGERS') ? require('../hooks/useScheduledTasks.js').useScheduledTasks : null;
+const useScheduledTasks = require('../hooks/useScheduledTasks.js').useScheduledTasks;
 /* eslint-enable @typescript-eslint/no-require-imports */
 import { isAgentSwarmsEnabled } from '../utils/agentSwarmsEnabled.js';
 import { useTaskListWatcher } from '../hooks/useTaskListWatcher.js';
@@ -4047,16 +4047,9 @@ export function REPL({
   });
 
   // Scheduled tasks from .claude/scheduled_tasks.json (CronCreate/Delete/List)
-  if (feature('AGENT_TRIGGERS')) {
-    // Assistant mode bypasses the isLoading gate (the proactive tick →
-    // Sleep → tick loop would otherwise starve the scheduler).
-    // kairosEnabled is set once in initialState (main.tsx) and never mutated — no
-    // subscription needed. The tengu_kairos_cron runtime gate is checked inside
-    // useScheduledTasks's effect (not here) since wrapping a hook call in a dynamic
-    // condition would break rules-of-hooks.
+  {
     const assistantMode = store.getState().kairosEnabled;
-    // biome-ignore lint/correctness/useHookAtTopLevel: feature() is a compile-time constant
-    useScheduledTasks!({
+    useScheduledTasks({
       isLoading,
       assistantMode,
       setMessages