[MM-67981] Add process ID (PID) to support packet diagnostics (#35832)

Populate server.process_id in diagnostics.yaml using os.Getpid(), making it easier to correlate support packet data with OS-level logs and confirm whether the server was restarted between an incident and packet generation.

Co-authored-by: Claude Sonnet 4.6 (1M context) <noreply@anthropic.com>

server/channels/app/platform/support_packet.go

@@ -117,6 +117,7 @@ func (ps *PlatformService) getSupportPacketDiagnostics(rctx request.CTX) (*model
 		installationType = unknownDataPoint
 	}
 	d.Server.InstallationType = installationType
+	d.Server.ProcessID = os.Getpid()
 
 	/* Config */
 	d.Config.Source = ps.DescribeConfig()

server/channels/app/platform/support_packet_test.go

@@ -209,6 +209,7 @@ func TestGetSupportPacketDiagnostics(t *testing.T) {
 		assert.Equal(t, "docker", d.Server.InstallationType)
 		assert.Positive(t, d.Server.CPUCores)
 		assert.Positive(t, d.Server.TotalMemoryMB)
+		assert.Positive(t, d.Server.ProcessID)
 
 		/* Config */
 		assert.Equal(t, "memory://", d.Config.Source)

server/public/model/support_packet.go

@@ -30,6 +30,7 @@ type SupportPacketDiagnostics struct {
 		CPUCores         int    `yaml:"cpu_cores"`
 		TotalMemoryMB    uint64 `yaml:"total_memory_mb"`
 		Hostname         string `yaml:"hostname"`
+		ProcessID        int    `yaml:"process_id"`
 		Version          string `yaml:"version"`
 		BuildHash        string `yaml:"build_hash"`
 		InstallationType string `yaml:"installation_type"`