fix(task-tool): add task ID validation and improve lock acquisition safety

- Add task ID pattern validation (T-[A-Za-z0-9-]+) to prevent path traversal
- Refactor lock mechanism to use UUID-based IDs for reliable ownership tracking
- Implement atomic lock creation with stale lock detection and cleanup
- Add lock acquisition checks in create/update/delete handlers
- Expand task-reminder hook to track split tool names and clean up on session deletion
- Add comprehensive test coverage for validation and lock handling

src/hooks/task-reminder/index.test.ts

@@ -122,4 +122,29 @@ describe("TaskReminderHook", () => {
     expect(output1.output).toContain("task tools haven't been used")
     expect(output2.output).not.toContain("task tools haven't been used")
   })
+
+  test("cleans up counters on session.deleted", async () => {
+    //#given
+    const sessionID = "test-session"
+    const output = { output: "Result" }
+
+    //#when
+    for (let i = 0; i < 10; i++) {
+      await hook["tool.execute.after"]?.(
+        { tool: "bash", sessionID, callID: `call-${i}` },
+        output
+      )
+    }
+    await hook.event?.({ event: { type: "session.deleted", properties: { info: { id: sessionID } } } })
+    const outputAfterDelete = { output: "Result" }
+    for (let i = 0; i < 9; i++) {
+      await hook["tool.execute.after"]?.(
+        { tool: "bash", sessionID, callID: `call-after-${i}` },
+        outputAfterDelete
+      )
+    }
+
+    //#then
+    expect(outputAfterDelete.output).not.toContain("task tools haven't been used")
+  })
 })

src/hooks/task-reminder/index.ts

@@ -1,10 +1,17 @@
 import type { PluginInput } from "@opencode-ai/plugin"
 
-const TASK_TOOLS = new Set(["task"])
+const TASK_TOOLS = new Set([
+  "task",
+  "task_create",
+  "task_list",
+  "task_get",
+  "task_update",
+  "task_delete",
+])
 const TURN_THRESHOLD = 10
 const REMINDER_MESSAGE = `
 
-The task tools haven't been used recently. If you're working on tasks that would benefit from tracking progress, consider using TaskCreate to add new tasks and TaskUpdate to update task status (set to in_progress when starting, completed when done).`
+The task tools haven't been used recently. If you're tracking work, use task with action=create/update (or task_create/task_update) to record progress.`
 
 interface ToolExecuteInput {
   tool: string
@@ -41,5 +48,12 @@ export function createTaskReminderHook(_ctx: PluginInput) {
 
   return {
     "tool.execute.after": toolExecuteAfter,
+    event: async ({ event }: { event: { type: string; properties?: unknown } }) => {
+      if (event.type !== "session.deleted") return
+      const props = event.properties as { info?: { id?: string } } | undefined
+      const sessionId = props?.info?.id
+      if (!sessionId) return
+      sessionCounters.delete(sessionId)
+    },
   }
 }