Auto-clear completed todo trees

README.md

@@ -98,7 +98,7 @@ A task starts timing the first time it enters `in-progress`. Leaving that state
 
 ## Pi Widget
 
-The widget appears above Pi's editor while todos exist. Run `/todo` to hide or show it for the current Pi runtime. Its header is the virtual task-tree root, with connectors extending from it through every top-level task so the display always remains a tree. The outline uses only the labels needed by the deepest task: one-level trees render every task as an unlabeled leaf, two-level trees use numbered parents and unlabeled leaves, and three-level trees use Roman-numeral categories, numbered items, and unlabeled leaves. Internal task IDs remain unchanged and visible in tool output. In-progress circles rotate through `◐ ◓ ◑ ◒` twice per second; other status symbols remain still. The widget shows at most 12 task rows plus a compact count of hidden tasks, so larger plans do not crowd the editor out of an 80×24 terminal.
+The widget appears above Pi's editor while todos exist. Run `/todo` to hide or show it for the current Pi runtime. Ten seconds after every task is completed, the task tree is automatically deleted and task IDs reset to `1`; adding or reopening unfinished work during that delay cancels the clear. Its header is the virtual task-tree root, with connectors extending from it through every top-level task so the display always remains a tree. The outline uses only the labels needed by the deepest task: one-level trees render every task as an unlabeled leaf, two-level trees use numbered parents and unlabeled leaves, and three-level trees use Roman-numeral categories, numbered items, and unlabeled leaves. Internal task IDs remain unchanged and visible in tool output. In-progress circles rotate through `◐ ◓ ◑ ◒` twice per second; other status symbols remain still. The widget shows at most 12 task rows plus a compact count of hidden tasks, so larger plans do not crowd the editor out of an 80×24 terminal.
 
 ```text
  Todos 2/6 · !1  ━━━━━────────