gofmt: bring internal/ and cmd/ back to gofmt -l clean

Mechanical `gofmt -w ./internal ./cmd`. Mostly struct-field realignment that
had drifted, plus a few trailing-newline fixes. No behaviour change — gofmt is
semantics-preserving, and build/vet/test are green either side.

Split out from the code-review fixes that follow so those stay reviewable
instead of hiding inside a wall of realignment.

internal/plugin/adventure_housing_test.go

@@ -144,10 +144,10 @@ func TestHouseHPBonus(t *testing.T) {
 		expected float64
 	}{
 		{0, 0},
-		{1, 0},     // Base house — no bonus
-		{2, 0.05},  // Livable
-		{3, 0.12},  // Comfortable
-		{4, 0.20},  // Established
+		{1, 0},    // Base house — no bonus
+		{2, 0.05}, // Livable
+		{3, 0.12}, // Comfortable
+		{4, 0.20}, // Established
 	}
 	for _, tt := range tests {
 		char := &AdventureCharacter{HouseTier: tt.tier}