Limit and label task hierarchy

README.md

@@ -90,7 +90,7 @@ Example append call:
 
 Task input keys are explicit so strict tool-schema bridges do not invent values for omitted properties. Use `description: null` when no detail is needed, `status: "pending"` for the default state, `parentId: null` for root tasks and nested children, and `children: []` for leaves. `prepareArguments` still expands legacy calls that omit these fields.
 
-To keep model-generated input safe and bounded, a session may contain up to 200 tasks. One mutation may affect up to 50 explicitly supplied tasks, hierarchy depth is limited to eight levels, names to 200 Unicode characters, and descriptions to 4,000 Unicode characters. Names and descriptions reject terminal controls and bidirectional override characters; descriptions may still contain line feeds for normal multi-line detail.
+To keep model-generated input safe and bounded, a session may contain up to 200 tasks. One mutation may affect up to 50 explicitly supplied tasks. The widget header acts as a virtual root above three stored task levels: categories, items, and leaf sub-items. Names are limited to 200 Unicode characters and descriptions to 4,000 Unicode characters. Names and descriptions reject terminal controls and bidirectional override characters; descriptions may still contain line feeds for normal multi-line detail.
 
 IDs are not reused by append/remove operations; `replace` deliberately rebuilds IDs from `1`. Replace forbids non-null `parentId`, so new hierarchy must use nested `children`. Multiple tasks may be `in-progress`. A parent can be marked `done` only when all descendants are also `done`.
 
@@ -98,14 +98,15 @@ A task starts timing the first time it enters `in-progress`. Leaving that state
 
 ## Pi Widget
 
-The widget appears above Pi's editor while tasks exist. Run `/tasks` to hide or show it for the current Pi runtime. It 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 tasks exist. Run `/tasks` to hide or show it for the current Pi runtime. Its header is the virtual task-tree root. Root tasks render as Roman-numeral categories, their children as numbered items, and leaf sub-items use indentation without another label. Internal task IDs remain unchanged and visible in tool output. 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
  Tasks 2/6 · !1  ━━━━━────────
-  ◉ 1. Build auth · 12:08
-  ├─ ! 3. Resolve token issue · 03:41
-  └─ ○ 4. Add middleware
-  ✓ 2. Define schema · 04:31
+  I. ◉ Build auth · 12:08
+  ├─ 1. ! Resolve token issue · 03:41
+  │  └─ ○ Inspect provider response
+  └─ 2. ○ Add middleware
+  II. ✓ Define schema · 04:31
 ```
 
 Tool calls remain compact in the conversation. Expand a tool result with Pi's normal tool-output shortcut to inspect affected tasks or full descriptions.