merge: resolve master conflicts for #259 subagent tool-budget docs

Integrate split-workflow router SKILL.md (#333) with subagent tool-budget
guardrails (#259). Keep shell spawn hard-stop (#258) and subagent
delegation (#266) operator-guide rules alongside subagent_tool_budget.

tests/test_operator_guide.py

@@ -134,7 +134,8 @@ class TestControlPlaneGuide(GuideTestBase):
                     "merge_confirmation", "redaction", "separation",
                     "profile_switching", "identity_verification",
                     "work_selection", "global_worktree",
-                    "subagent_tool_budget"):
+                    "shell_spawn_hard_stop", "subagent_tool_budget",
+                    "subagent_delegation"):
             self.assertIn(key, rules)
         self.assertIn("MERGE PR", json.dumps(rules["merge_confirmation"]))
         self.assertTrue(rules["hard_stops"])