fix(tasks-hook): share task_system resolution

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

src/hooks/tasks-todowrite-disabler/hook.test.ts

@@ -0,0 +1,40 @@
+import { describe, expect, test } from "bun:test"
+
+import { REPLACEMENT_MESSAGE } from "./constants"
+import { createTasksTodowriteDisablerHook } from "./hook"
+
+describe("createTasksTodowriteDisablerHook", () => {
+  describe("#given experimental.task_system is omitted", () => {
+    test("#when TodoWrite runs #then it is allowed by default", async () => {
+      // given
+      const hook = createTasksTodowriteDisablerHook({})
+
+      // when
+      const result = hook["tool.execute.before"](
+        { tool: "TodoWrite", sessionID: "ses_123", callID: "call_123" },
+        { args: {} },
+      )
+
+      // then
+      await expect(result).resolves.toBeUndefined()
+    })
+  })
+
+  describe("#given experimental.task_system is enabled", () => {
+    test("#when TodoWrite runs #then it is blocked", async () => {
+      // given
+      const hook = createTasksTodowriteDisablerHook({
+        experimental: { task_system: true },
+      })
+
+      // when
+      const result = hook["tool.execute.before"](
+        { tool: "TodoWrite", sessionID: "ses_123", callID: "call_123" },
+        { args: {} },
+      )
+
+      // then
+      await expect(result).rejects.toThrow(REPLACEMENT_MESSAGE)
+    })
+  })
+})

src/hooks/tasks-todowrite-disabler/hook.ts

@@ -1,3 +1,4 @@
+import { isTaskSystemEnabled } from "../../shared/task-system-enabled";
 import { BLOCKED_TOOLS, REPLACEMENT_MESSAGE } from "./constants";
 
 export interface TasksTodowriteDisablerConfig {
@@ -9,14 +10,14 @@ export interface TasksTodowriteDisablerConfig {
 export function createTasksTodowriteDisablerHook(
   config: TasksTodowriteDisablerConfig,
 ) {
-  const isTaskSystemEnabled = config.experimental?.task_system ?? true;
+  const taskSystemEnabled = isTaskSystemEnabled(config);
 
   return {
     "tool.execute.before": async (
       input: { tool: string; sessionID: string; callID: string },
       _output: { args: Record<string, unknown> },
     ) => {
-      if (!isTaskSystemEnabled) {
+      if (!taskSystemEnabled) {
         return;
       }