refactor(runtime): split core and tool hotspots

- Extract config, session-state, review, and tool helpers for structural lint cleanup

- Keep runtime schemas and tool result behavior unchanged

Co-Authored-By: devagent <devagent@egavrin>

Author: egavrin

packages/runtime/src/core/approval.test.ts

@@ -40,8 +40,6 @@ function makeSafetyPolicy(
     ...overrides,
   };
 }
-
-describe("ApprovalGate", () => {
   describe("Suggest mode", () => {
     it("allows readonly tools", () => {
       const gate = new ApprovalGate(makePolicy());
@@ -565,4 +563,3 @@ describe("ApprovalGate", () => {
       expect(events).toHaveLength(0);
     });
   });
-});