fix(tests): stop racing a live broker daemon against direct-SQL tests

test-all/test-ci started the standalone pgsql-broker binary via
broker-start before running the Go integration suite, leaving its
background workers polling queue 1/2 against broker_test for the
whole run. TestBrokerWorkflow already starts its own in-process
broker and needs no external daemon, and nothing else in the suite
uses it. The redundant daemon's worker could steal-claim a job that
stage5_test.go's TestJobDependencies or
TestFailedJobRetriesThenCompletesWithoutStranding had just inserted
before the test's own broker_get call ran, intermittently failing
those assertions. Drop broker-start/broker-stop from the test
targets; the standalone targets remain for manual use.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

Makefile

@@ -70,9 +70,9 @@ test-local-unit: deps ## Run local unit tests
 	@echo "Running local unit tests..."
 	@$(GO) test -v -race -cover $(shell $(GO) list ./... | grep -v /tests/integration)
 
-test-all: test-teardown test-setup test-connection schema-install broker-start test-local-unit test-integration-go broker-stop test-teardown ## Run all unit and integration tests (starts its own Postgres via docker-compose)
+test-all: test-teardown test-setup test-connection schema-install test-local-unit test-integration-go test-teardown ## Run all unit and integration tests (starts its own Postgres via docker-compose)
 
-test-ci: test-connection schema-install broker-start test-local-unit test-integration-go broker-stop ## Run all unit and integration tests against an externally-provided Postgres (CI services: block)
+test-ci: test-connection schema-install test-local-unit test-integration-go ## Run all unit and integration tests against an externally-provided Postgres (CI services: block)
 
 test-connection: deps ## Test database connection with retry
 	@echo "Testing database connection (host=$(TEST_DB_HOST) port=$(TEST_DB_PORT))..."