fix(ui): F8-06 calculator polish — drop delete-class button, reserve lock slot

- Remove the `delete <ship_class_name>` button (and `deleteClass`,
  `canDelete`, `.delete` CSS, `game.calculator.action.delete` i18n key)
  from the calculator. Delete-class lives in the ship-classes table —
  the broader rework will land under #53.
- Bombing and cargo-capacity rows now reserve a hidden lock-slot
  placeholder so their value column lines up vertically with the
  mass/speed/attack/defence rows (which carry a lock button).

ui/frontend/tests/calculator-tab.test.ts

@@ -628,4 +628,40 @@ describe("calculator-tab", () => {
 		expect(ui.getByTestId("calculator-block-drive")).toHaveValue(3);
 		confirm.mockRestore();
 	});
+
+	test("does not render a delete-class button after loading a class", async () => {
+		const ui = mount({
+			report: makeReport({
+				localShipClass: [
+					{
+						name: "Scout",
+						drive: 3,
+						armament: 0,
+						weapons: 0,
+						shields: 2,
+						cargo: 1,
+					},
+				],
+			} as unknown as GameReport),
+		});
+		await fireEvent.input(ui.getByTestId("calculator-name"), {
+			target: { value: "Scout" },
+			inputType: "insertReplacementText",
+		});
+		// The loaded class state used to render a `delete <name>` button;
+		// the calculator no longer owns delete-class — issue #53 will.
+		expect(ui.queryByTestId("calculator-delete")).toBeNull();
+	});
+
+	test("bombing and cargo-capacity rows reserve the lock slot for column alignment", () => {
+		const ui = mount();
+		for (const id of ["calculator-out-bombing", "calculator-out-cargo-capacity"]) {
+			const cell = ui.getByTestId(id).parentElement;
+			expect(cell).not.toBeNull();
+			// A hidden placeholder occupies the same width as the lock button
+			// on the mass/speed/attack/defence rows, so the value column does
+			// not drift right on the rows without a lock.
+			expect(cell!.querySelector(".lock-slot")).not.toBeNull();
+		}
+	});
 });