docs(6856): the scope section says the cross-project rule in fewer lines, so using-grimoire fits its 350-line budget

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

plugin/skills/using-grimoire/SKILL.md

@@ -277,16 +277,12 @@ bound — confine the session to it:
 - **Pass that `project_id` to every read** (`search`, `list_tasks`,
   `list_notes`). An unscoped read bleeds every other project's work into your
   context.
-- **Only reference or offer work on the in-scope project.** Don't surface,
-  suggest, or start work on other projects unless the operator explicitly widens
-  scope.
-- **Toward another project, the one change to make is filing an issue**:
-  `create_task(project_id=<theirs>, kind="issue")`, carrying how you found it
-  and the evidence. Editing its files, committing or pushing in its repo, and
-  changing its other records are the operator's call, and the plugin asks them
-  before any of those runs. Reading anything there is fine.
-- If the work itself belongs to a *different* project, say so and **ask before
-  switching** — never silently operate cross-project.
+- **Only reference or offer work on the in-scope project**, unless the
+  operator explicitly widens scope; work that belongs elsewhere, say so and ask.
+- **Cross-project, the one change to make is filing an issue**:
+  `create_task(project_id=<theirs>, kind="issue")` with how you found it and the
+  evidence. Reading there is fine; editing its files, committing or pushing in
+  its repo, or changing its records is the operator's call, and the plugin asks.
 
 ## Read these when the moment comes