chore: decrease daemon resource pre allocation

spinifex/daemon/resource.go

@@ -25,7 +25,7 @@ type hostReserve struct {
 
 // defaultHostReserve is sized to cover predastore + viperblock under load;
 // the daemon itself needs little.
-var defaultHostReserve = hostReserve{vCPU: 2, memGB: 4.0}
+var defaultHostReserve = hostReserve{vCPU: 2, memGB: 2.0}
 
 // minHostMemHeadroomGB is the minimum schedulable memory we require above
 // the reserve, so a host that just meets the reserve still has a small

spinifex/daemon/resource_test.go

@@ -226,15 +226,15 @@ func TestApplyHostReserve(t *testing.T) {
 			totalVCPU:  16,
 			totalMemGB: 64.0,
 			wantVCPU:   2,
-			wantMem:    4.0,
+			wantMem:    2.0,
 		},
 		{
-			name:       "boundary host (3 vCPU, 4.5 GB)",
+			name:       "boundary host (3 vCPU, 2.5 GB)",
 			host:       defaultHostReserve,
 			totalVCPU:  3,
-			totalMemGB: 4.5,
+			totalMemGB: 2.5,
 			wantVCPU:   2,
-			wantMem:    4.0,
+			wantMem:    2.0,
 		},
 		{
 			name:       "too small: vCPU equals reserve",
@@ -254,14 +254,14 @@ func TestApplyHostReserve(t *testing.T) {
 			name:       "too small: mem at reserve threshold (no headroom)",
 			host:       defaultHostReserve,
 			totalVCPU:  8,
-			totalMemGB: 4.0,
+			totalMemGB: 2.0,
 			wantErr:    true,
 		},
 		{
 			name:       "too small: mem just under reserve+headroom",
 			host:       defaultHostReserve,
 			totalVCPU:  8,
-			totalMemGB: 4.49,
+			totalMemGB: 2.49,
 			wantErr:    true,
 		},
 		{