ui/phase-15: planet inspector production controls + order-draft collapse

Adds the second end-to-end command (`setProductionType`) with a
collapse-by-`planetNumber` rule on the order draft, the segmented
production-controls component on the planet inspector, the FBS
encoder/decoder pair for `CommandPlanetProduce`, and the
`localShipClass` projection on `GameReport`. Forecast number is
deferred and tracked in the new `ui/docs/calc-bridge.md`.

ui/frontend/src/api/game-state.ts

@@ -15,6 +15,11 @@
 // rename in the local draft swaps the planet name on the rendered
 // report so the player sees their intent reflected immediately,
 // without waiting for the next turn cutoff.
+//
+// Phase 15 extends the projection with a minimal `localShipClass`
+// summary so the planet inspector's Build-Ship sub-picker has data
+// to render. Phase 17 (ship-class CRUD) widens `ShipClassSummary`
+// when the designer ships need the full attribute set.
 
 import { Builder, ByteBuffer } from "flatbuffers";
 
@@ -24,7 +29,11 @@ import {
 	GameReportRequest,
 	Report,
 } from "../proto/galaxy/fbs/report";
-import type { CommandStatus, OrderCommand } from "../sync/order-types";
+import type {
+	CommandStatus,
+	OrderCommand,
+	ProductionType,
+} from "../sync/order-types";
 
 const MESSAGE_TYPE = "user.games.report";
 
@@ -61,6 +70,18 @@ export interface ReportPlanet {
 	freeIndustry: number | null;
 }
 
+/**
+ * ShipClassSummary is the slim projection of `report.ShipClass` the
+ * planet inspector's Build-Ship sub-picker needs in Phase 15. Only
+ * the human-visible `name` is carried — the engine command shape
+ * (`CommandPlanetProduce.subject`) takes the class name, not its
+ * underlying tech values. Phase 17 widens this type when the ship
+ * designer needs the full attribute set.
+ */
+export interface ShipClassSummary {
+	name: string;
+}
+
 export interface GameReport {
 	turn: number;
 	mapWidth: number;
@@ -73,6 +94,14 @@ export interface GameReport {
 	 * has not produced a report yet (boot state).
 	 */
 	race: string;
+	/**
+	 * localShipClass enumerates the player's own designed ship classes
+	 * by name. Empty until at least one class is created
+	 * (`CommandShipClassCreate`, Phase 17). The Build-Ship sub-picker
+	 * shows a localized "no ship classes" placeholder when this is
+	 * empty.
+	 */
+	localShipClass: ShipClassSummary[];
 }
 
 export async function fetchGameReport(
@@ -189,6 +218,13 @@ function decodeReport(report: Report): GameReport {
 		});
 	}
 
+	const localShipClass: ShipClassSummary[] = [];
+	for (let i = 0; i < report.localShipClassLength(); i++) {
+		const sc = report.localShipClass(i);
+		if (sc === null) continue;
+		localShipClass.push({ name: sc.name() ?? "" });
+	}
+
 	return {
 		turn: Number(report.turn()),
 		mapWidth: report.width(),
@@ -196,6 +232,7 @@ function decodeReport(report: Report): GameReport {
 		planetCount: report.planetCount(),
 		planets,
 		race: report.race() ?? "",
+		localShipClass,
 	};
 }
 
@@ -221,10 +258,12 @@ export function uuidToHiLo(value: string): [bigint, bigint] {
 /**
  * applyOrderOverlay returns a copy of `report` with every locally-
  * valid or still-in-flight or applied command from `commands`
- * projected on top. Phase 14 understands `planetRename` only —
- * every other variant passes through. The function is pure:
- * callers re-derive the overlay whenever the draft or the report
- * change.
+ * projected on top. Phase 14 introduced the overlay for
+ * `planetRename`; Phase 15 extends it to `setProductionType` so the
+ * inspector segment / map label reflect the chosen production target
+ * before the engine confirms it. Other variants pass through. The
+ * function is pure: callers re-derive the overlay whenever the draft
+ * or the report change.
  *
  * `statuses` maps command id → status. Entries with `valid`,
  * `submitting`, or `applied` participate in the overlay — together
@@ -250,18 +289,69 @@ export function applyOrderOverlay(
 		) {
 			continue;
 		}
-		if (cmd.kind !== "planetRename") continue;
-		const idx = report.planets.findIndex((p) => p.number === cmd.planetNumber);
-		if (idx < 0) continue;
-		if (mutatedPlanets === null) {
-			mutatedPlanets = [...report.planets];
+		if (cmd.kind === "planetRename") {
+			const idx = report.planets.findIndex(
+				(p) => p.number === cmd.planetNumber,
+			);
+			if (idx < 0) continue;
+			if (mutatedPlanets === null) {
+				mutatedPlanets = [...report.planets];
+			}
+			mutatedPlanets[idx] = { ...mutatedPlanets[idx]!, name: cmd.name };
+			continue;
+		}
+		if (cmd.kind === "setProductionType") {
+			const idx = report.planets.findIndex(
+				(p) => p.number === cmd.planetNumber,
+			);
+			if (idx < 0) continue;
+			if (mutatedPlanets === null) {
+				mutatedPlanets = [...report.planets];
+			}
+			mutatedPlanets[idx] = {
+				...mutatedPlanets[idx]!,
+				production: productionDisplayFromCommand(
+					cmd.productionType,
+					cmd.subject,
+				),
+			};
+			continue;
 		}
-		mutatedPlanets[idx] = { ...mutatedPlanets[idx]!, name: cmd.name };
 	}
 	if (mutatedPlanets === null) return report;
 	return { ...report, planets: mutatedPlanets };
 }
 
+/**
+ * productionDisplayFromCommand mirrors the engine's
+ * `Cache.PlanetProductionDisplayName`
+ * (`game/internal/controller/planet.go`) for the optimistic overlay.
+ * Keeping the strings byte-equal with the next server report avoids
+ * a flicker when the overlay drops on the next turn cutoff.
+ */
+export function productionDisplayFromCommand(
+	productionType: ProductionType,
+	subject: string,
+): string {
+	switch (productionType) {
+		case "MAT":
+			return "Material";
+		case "CAP":
+			return "Capital";
+		case "DRIVE":
+			return "Drive";
+		case "WEAPONS":
+			return "Weapons";
+		case "SHIELDS":
+			return "Shields";
+		case "CARGO":
+			return "Cargo";
+		case "SCIENCE":
+		case "SHIP":
+			return subject;
+	}
+}
+
 function decodeErrorMessage(payload: Uint8Array): { code: string; message: string } {
 	if (payload.length === 0) {
 		return { code: "internal_error", message: "empty error payload" };