docs(todo): state the catalog's policy branch and drop the sidecar census

The tool catalog boots every tool with its default config, but
allowParallelInProgress has no default, so the generator has to choose;
the page now says which branch it shows. The Agent Note's sidecar count
went stale twice inside this PR, so it records the refresh rule instead
of a point-in-time census. The SDK builtin entry pins its config literal
with satisfies like every sibling.

packages/client/connection/tests/fixture.spec.ts

@@ -242,8 +242,8 @@ describe('createFixtureApi', () => {
     const times = events.slice(todoAt - 1, todoAt + 2).map(e => e.time)
     expect(times[0]).toBeLessThanOrEqual(times[1] ?? 0)
     expect(times[1]).toBeLessThanOrEqual(times[2] ?? 0)
-    // The sample is a parallel plan: the tool permits several in_progress, so
-    // the surfaces fed from here are exercised against more than one active item.
+    // The sample is a parallel plan: this fixture chooses the parallel policy,
+    // so the surfaces fed from here face more than one active item.
     const snapshot = events[todoAt] as { data: { todos: { status: string }[] } }
     expect(snapshot.data.todos.filter(t => t.status === 'in_progress')).toHaveLength(2)
   })