test: enforce structured UDS timeout failures

CodeRabbit's follow-up surfaced a real consistency gap: UDS send socket errors used UdsPeerConnectionError while response timeouts still rejected a generic Error. Timeouts now use the same structured peer failure contract, and the test exercises that path through a short explicit timeout instead of waiting for the production default.

The AgentSummary unchanged-fingerprint test now also asserts that the second unchanged tick does not log errors, preserving the existing behavior checks without changing production scheduling semantics.

Constraint: Keep the production timeout default at 5000ms while allowing tests to exercise the timeout path quickly.

Rejected: Leave timeout failures as generic Error | callers would need separate handling for the same peer connection failure class.

Confidence: high

Scope-risk: narrow

Directive: Keep UDS send timeout and socket-error branches on the same structured error contract.

Tested: bun test src/services/AgentSummary/__tests__/agentSummary.test.ts src/utils/__tests__/udsMessaging.test.ts

Tested: bunx tsc --noEmit --pretty false

Tested: bun run lint

Tested: bun run test:all

Tested: bun test --coverage --coverage-reporter lcov --coverage-dir coverage

Tested: bun run build

Tested: bun run build:vite

Not-tested: GitHub-hosted CodeRabbit refresh until pushed.

src/services/AgentSummary/__tests__/agentSummary.test.ts

@@ -134,6 +134,7 @@ describe('startAgentSummarization', () => {
 
     expect(forkCalls).toHaveLength(1)
     expect(updateCalls).toHaveLength(1)
+    expect(loggedErrors).toEqual([])
   })
 
   test('skips summarization when filtering leaves too little bounded context', async () => {