fix(test): unique project names for pi-agent FullChain e2e

Fixed Chinese names collided on reused gate-pg across nightly runs.

internal/server/workflow_governance_piagent_pg_test.go

@@ -266,7 +266,7 @@ func TestWorkflowGovernance_PiAgent_PG_FullChain(t *testing.T) {
 		WfKey:       workflowdef.OfficialKeyMain,
 		TaskKey:     "intake",
 		StageKey:    "V0.1_triage",
-		ProjectName: "PG PiAgent 治理链中文项目",
+		ProjectName: fmt.Sprintf("PG PiAgent 治理链 %d", time.Now().UnixNano()%1_000_000),
 		Materials: []bizdev.MaterialInput{{
 			Filename: "project_brief.md",
 			Content:  []byte("# 项目简报\n\n- 产品：超声软组织手术系统\n- 目标：NMPA III 类注册路径摸底\n- 关键需求：双频刀头、灌注与负压吸引\n"),
@@ -280,7 +280,7 @@ func TestWorkflowGovernance_PiAgent_PG_ProductManager_FullChain(t *testing.T) {
 		WfKey:              workflowdef.OfficialKeyProductManager,
 		TaskKey:            "system_reqs",
 		StageKey:           "requirements_baseline",
-		ProjectName:        "PG PiAgent 产品经理治理链",
+		ProjectName:        fmt.Sprintf("PG PiAgent 产品经理 %d", time.Now().UnixNano()%1_000_000),
 		ExpectPlanningDone: true,
 		Materials: []bizdev.MaterialInput{{
 			Filename: "intake_summary.md",
@@ -295,7 +295,7 @@ func TestWorkflowGovernance_PiAgent_PG_TestManager_FullChain(t *testing.T) {
 		WfKey:              workflowdef.OfficialKeyTestManager,
 		TaskKey:            "test_manager",
 		StageKey:           "system_verification_planning",
-		ProjectName:        "PG PiAgent 测试经理治理链",
+		ProjectName:        fmt.Sprintf("PG PiAgent 测试经理 %d", time.Now().UnixNano()%1_000_000),
 		ExpectPlanningDone: true,
 		Materials: []bizdev.MaterialInput{{
 			Filename: "verification_scope.md",