Merge branch 'fix/m2-pr-e-agent-service'

PR-E of 6: AgentService ctx-first collapse.

Collapses the HeartbeatWithContext wrapper into a single Heartbeat
method. Handler-facing method name is preserved (D-4); the handler
service interface and mock already expected ctx-first, so this PR
touches only the service layer and its tests (4 files, 9+/15-).

Verification on the feature branch: build, vet, test (-short),
test -race, full-module test -short, and golangci-lint all clean.

Audit complete. Commit: 1f6cf0eafa. Sections: 12. Findings: 2/7/10/4/6.

internal/service/agent.go

@@ -91,8 +91,8 @@ func (s *AgentService) Register(ctx context.Context, name string, hostname strin
 	return agent, apiKey, nil
 }
 
-// HeartbeatWithContext updates an agent's last seen time, status, and metadata.
+// Heartbeat updates an agent's last seen time, status, and metadata.
-func (s *AgentService) HeartbeatWithContext(ctx context.Context, agentID string, metadata *domain.AgentMetadata) error {
+func (s *AgentService) Heartbeat(ctx context.Context, agentID string, metadata *domain.AgentMetadata) error {
 	agent, err := s.agentRepo.Get(ctx, agentID)
 	if err != nil {
 		return fmt.Errorf("failed to fetch agent: %w", err)
@@ -114,12 +114,6 @@ func (s *AgentService) HeartbeatWithContext(ctx context.Context, agentID string,
 	return nil
 }
 
-// Heartbeat updates agent heartbeat (handler interface method).
-// Note: This method is called from handlers which have a context; callers should prefer HeartbeatWithContext.
-func (s *AgentService) Heartbeat(ctx context.Context, agentID string, metadata *domain.AgentMetadata) error {
-	return s.HeartbeatWithContext(ctx, agentID, metadata)
-}
-
 // SubmitCSR validates and processes a Certificate Signing Request from an agent.
 // In agent keygen mode, this completes an AwaitingCSR renewal job by signing the CSR
 // and storing the cert version. The private key stays on the agent — only the CSR

internal/service/agent_test.go

@@ -92,7 +92,7 @@ func TestHeartbeat(t *testing.T) {
 
 	agentService := NewAgentService(agentRepo, certRepo, jobRepo, targetRepo, auditService, issuerRegistry, nil)
 
-	err := agentService.HeartbeatWithContext(ctx, "agent-001", nil)
+	err := agentService.Heartbeat(ctx, "agent-001", nil)
 	if err != nil {
 		t.Fatalf("Heartbeat failed: %v", err)
 	}
@@ -125,7 +125,7 @@ func TestHeartbeat_NotFound(t *testing.T) {
 
 	agentService := NewAgentService(agentRepo, certRepo, jobRepo, targetRepo, auditService, issuerRegistry, nil)
 
-	err := agentService.HeartbeatWithContext(ctx, "nonexistent", nil)
+	err := agentService.Heartbeat(ctx, "nonexistent", nil)
 	if err == nil {
 		t.Fatal("expected error for nonexistent agent")
 	}

internal/service/concurrent_test.go

@@ -159,7 +159,7 @@ func TestConcurrentAgentHeartbeats(t *testing.T) {
 				Architecture: "x86_64",
 			}
 
-			err := agentSvc.HeartbeatWithContext(ctx, agentID, metadata)
+			err := agentSvc.Heartbeat(ctx, agentID, metadata)
 			if err != nil {
 				errChan <- fmt.Errorf("goroutine %d: failed heartbeat for agent %s: %w", idx, agentID, err)
 				return

internal/service/context_test.go

@@ -176,13 +176,13 @@ func TestAgentService_HeartbeatWithCancelledContext(t *testing.T) {
 		nil, // renewalService
 	)
 
-	err := agentSvc.HeartbeatWithContext(ctx, "agent-1", &domain.AgentMetadata{})
+	err := agentSvc.Heartbeat(ctx, "agent-1", &domain.AgentMetadata{})
 
 	// Service should handle cancelled context
 	if err == nil || ctx.Err() == context.Canceled {
 		return
 	}
-	t.Logf("HeartbeatWithContext with cancelled context returned: %v", err)
+	t.Logf("Heartbeat with cancelled context returned: %v", err)
 }
 
 // Test with timeout context (should trigger deadline exceeded)
@@ -229,11 +229,11 @@ func TestAgentService_HeartbeatWithDeadlineExceeded(t *testing.T) {
 
 	time.Sleep(10 * time.Millisecond) // Ensure deadline is exceeded
 
-	err := agentSvc.HeartbeatWithContext(ctx, "agent-1", &domain.AgentMetadata{})
+	err := agentSvc.Heartbeat(ctx, "agent-1", &domain.AgentMetadata{})
 
 	// Service should handle deadline exceeded
 	if err == nil || ctx.Err() == context.DeadlineExceeded {
 		return
 	}
-	t.Logf("HeartbeatWithContext with deadline exceeded returned: %v", err)
+	t.Logf("Heartbeat with deadline exceeded returned: %v", err)
 }