feat: multi-work is able to delegate to root

docs/multi-work.md

@@ -1,13 +1,15 @@
 # Multi-work
 
 `multi-work` is a **primary-only** agent for coordinating independent work in
-Herdr-managed Git worktrees. Like `coordinate`, it uses the configured `deep-lo`
-model and effort, falling back to `good-lo` when `deep-lo` is unavailable. No
-extra custom model assignment is required.
+the current Herdr root checkout or new Herdr-managed Git worktrees. Like
+`coordinate`, it uses the configured `deep-lo` model and effort, falling back
+to `good-lo` when `deep-lo` is unavailable. No extra custom model assignment is
+required.
 
 ```text
 multi-work (root checkout)
 ├── fast-lo (local retrieval)
+├── coordinate (current root checkout)
 └── coordinate (new Herdr worktree)
     └── existing leaf workers (that worktree)
 ```
@@ -56,7 +58,24 @@ plugins or project configuration.
 
 ## Delegation
 
-Multi-work retains the native tool name, `subagent`. It adds one argument:
+Multi-work retains the native tool name, `subagent`. For work in the current root
+checkout, omit `worktree`:
+
+```js
+subagent({
+    agent: "coordinate",
+    description: "Implement local change",
+    prompt: "Goal, owned files, constraints, and acceptance checks...",
+    background: true,
+});
+```
+
+The child is bound to the verified root workspace before its prompt is admitted.
+No Herdr workspace is created and neither the child nor parent is moved. Root-local
+children share a checkout, so parallel assignments must have disjoint file ownership.
+Their placement metadata uses `branch: "root"` to identify the shared root checkout;
+it is not a claim about the root's current Git branch.
+Use a worktree when edits may overlap or require branch isolation:
 
 ```js
 subagent({
@@ -86,17 +105,22 @@ checkout path; the tool parses and verifies the returned checkout/workspace.
 Creation explicitly preserves focus with `--no-focus`.
 
 For focused retrieval, use native `subagent` with `agent: "fast-lo"` and no
-`worktree`. Resume an owned coordinate child with its `sessionID` and **omit**
-`worktree`. Resumes verify parent, agent, checkout, branch, and live Herdr ownership.
+`worktree`. A new coordinate call without `worktree` means root-local work. Resume
+an owned coordinate child with its `sessionID` and **omit**
+`worktree`. Resumes verify parent, agent, assigned checkout, and live Herdr ownership;
+worktree resumes also verify the branch.
 Bound coordinate children cannot be repurposed through native delegation.
 
 Neither multi-work nor coordinate has general shell/edit permissions. Multi-work
 also rejects non-reading/non-delegation tools at execution, including Code Mode,
-even if a session permission override would expose them. Worktree preparation
-requires effective `herdr_worktree: allow`, evaluated against the canonical root
-directory using ordered agent and session rules. `ask` fails explicitly because
-the public plugin API cannot request custom-tool approval. Native subagent
-permissions are still asserted by OpenCode before preparation starts.
+even if a session permission override would expose them. Creating or resuming
+worktree-backed delegation requires effective `herdr_worktree: allow`, evaluated
+against the canonical root directory using ordered agent and session rules. `ask`
+fails explicitly because the public plugin API cannot request custom-tool approval.
+Native subagent permissions are still asserted by OpenCode before preparation
+starts. Root-local delegation performs no Herdr creation and therefore does not
+require `herdr_worktree`; worker edit/shell permissions remain inherited and
+enforced normally.
 
 Worktree permissions inherit the base plugin's **effective build-permission
 snapshot**, including configuration applied after plugin transforms. Its existing
@@ -118,8 +142,8 @@ child ID, and confirm its actual session location before allowing the task promp
 A move-request acknowledgement alone is insufficient. Confirmation is bounded to
 30 seconds and remains interruptible. The parent session does not move.
 
-Coordinate is child-capable only through an owned, ready worktree binding. Prompt
-admission and model-context guards reject unbound or moved coordinate children.
+Coordinate is child-capable only through an owned, ready multi-work binding. Prompt
+admission and model-context guards reject unbound or relocated coordinate children.
 Multi-work cannot be a child, and the existing workers remain leaves.
 
 Normal delegation cards and child navigation recognize the retained `subagent`