ui/phase-17: ship-class CRUD without calc

Phase 17 lights up the ship-class table and designer active views,
extends the order-draft pipeline with createShipClass and
removeShipClass commands, and projects pending Save/Delete actions
through applyOrderOverlay so the table reflects the player's
intent before auto-sync lands. The plan is corrected in the same
patch: per game/rules.txt, ship classes are designed once and
cannot be edited — the engine has no Update command, so the UI
exposes only Create + Delete.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

ui/frontend/src/sync/order-draft.svelte.ts

@@ -27,6 +27,7 @@ import { fetchOrder } from "./order-load";
 import type { CommandStatus, OrderCommand } from "./order-types";
 import { submitOrder } from "./submit";
 import { validateEntityName } from "$lib/util/entity-name";
+import { validateShipClass } from "$lib/util/ship-class-validation";
 
 const NAMESPACE = "order-drafts";
 const draftKey = (gameId: string): string => `${gameId}/draft`;
@@ -487,6 +488,31 @@ function validateCommand(cmd: OrderCommand): CommandStatus {
 			// which the inspector enforces by only mounting the
 			// component on `kind === "local"`.
 			return "valid";
+		case "createShipClass":
+			// Mirrors `pkg/calc/validator.go.ValidateShipTypeValues`
+			// plus the entity-name rules. The duplicate-name check is
+			// the designer's responsibility (it sees the live overlay
+			// list); here the validator runs without `existingNames`
+			// so a draft that was valid at creation time does not flip
+			// to invalid just because another `createShipClass` for
+			// the same name landed in the draft afterwards — both
+			// rows ride out the wire and the engine arbitrates.
+			return validateShipClass({
+				name: cmd.name,
+				drive: cmd.drive,
+				armament: cmd.armament,
+				weapons: cmd.weapons,
+				shields: cmd.shields,
+				cargo: cmd.cargo,
+			}).ok
+				? "valid"
+				: "invalid";
+		case "removeShipClass":
+			// `removeShipClass` carries only the name; the engine
+			// checks that the class exists and is not referenced by
+			// active production / ship groups. Local validation only
+			// guards the name shape.
+			return validateEntityName(cmd.name).ok ? "valid" : "invalid";
 		case "placeholder":
 			// Phase 12 placeholder entries are content-free and never
 			// transition out of `draft` — they are not submittable.