perf(cmpp): instrument inbound flow and unbatch submit worker

api/src/send-chain/gateway-events.controller.spec.ts

@@ -11,7 +11,17 @@ describe('GatewayEventsController protocol logging', () => {
   const protocolLogs = {
     record: jest.fn(),
   };
-  const controller = new GatewayEventsController(sendChain as never, {} as never, protocolLogs as never, { recordEvent: jest.fn() } as never);
+  const metrics = {
+    beginCmppInboundStage: jest.fn().mockReturnValue(1n),
+    finishCmppInboundStage: jest.fn(),
+  };
+  const controller = new GatewayEventsController(
+    sendChain as never,
+    {} as never,
+    protocolLogs as never,
+    { recordEvent: jest.fn() } as never,
+    metrics as never,
+  );
 
   beforeEach(() => {
     jest.clearAllMocks();
@@ -77,6 +87,20 @@ describe('GatewayEventsController protocol logging', () => {
     }));
   });
 
+  it('records a failed inbound total without swallowing the service error', async () => {
+    const failure = new Error('inbound failed');
+    (sendChain as Record<string, jest.Mock>).submitInboundMessage = jest.fn().mockRejectedValue(failure);
+
+    await expect(controller.submitInbound({
+      account: '607532',
+      phoneNumber: '13127620092',
+      content: 'failed',
+      sequenceId: 142,
+    })).rejects.toBe(failure);
+
+    expect(metrics.finishCmppInboundStage).toHaveBeenCalledWith(1n, 'total', 'error');
+  });
+
   it('accepts only safe outbound Gateway packet events', () => {
     expect(controller.protocolLog({
       protocol: 'cmpp',
@@ -155,6 +179,7 @@ describe('GatewayEventsController protocol logging', () => {
       messageId: 'MSG-1',
       status: 'success',
     }));
+    expect(metrics.finishCmppInboundStage).toHaveBeenCalledWith(1n, 'total', 'success');
   });
 
   it('replaces a fallback receipt identifier with the resolved main message identifier', async () => {