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/docs/order-composer.md

@@ -95,7 +95,7 @@ stored value).
 
 `OrderCommand` is a discriminated union on the `kind` field. Phase
 12 shipped the skeleton with a single content-free variant; Phase
-14 adds the first real one:
+14 added the first real one and Phase 15 added the second:
 
 ```ts
 interface PlaceholderCommand {
@@ -111,7 +111,20 @@ interface PlanetRenameCommand {
     readonly name: string;
 }
 
-type OrderCommand = PlaceholderCommand | PlanetRenameCommand;
+interface SetProductionTypeCommand {
+    readonly kind: "setProductionType";
+    readonly id: string;
+    readonly planetNumber: number;
+    readonly productionType:
+        | "MAT" | "CAP" | "DRIVE" | "WEAPONS"
+        | "SHIELDS" | "CARGO" | "SCIENCE" | "SHIP";
+    readonly subject: string;
+}
+
+type OrderCommand =
+    | PlaceholderCommand
+    | PlanetRenameCommand
+    | SetProductionTypeCommand;
 ```
 
 The `id` field is the canonical identifier the store uses for
@@ -123,6 +136,35 @@ with the inline editor in `lib/inspectors/planet.svelte`, the
 local validator (`lib/util/entity-name.ts`, parity with
 `pkg/util/string.go.ValidateTypeName`), and the submit pipeline.
 
+`setProductionType` is the wire-mirror of the engine's
+`CommandPlanetProduce` (`pkg/model/order/order.go`). The local
+validator runs the same `subject=Production` rule as
+`game/internal/router/validator.go`: `subject` is required and
+must satisfy `validateEntityName` when `productionType` is
+`SCIENCE` or `SHIP`; otherwise it is the empty string. The
+optimistic overlay rewrites `planet.production` using
+`productionDisplayFromCommand` (`api/game-state.ts`), which
+mirrors the engine's `Cache.PlanetProductionDisplayName` so the
+overlay stays byte-equal with the next server report.
+
+### Collapse-by-target rule (Phase 15)
+
+`setProductionType` is the first variant to carry a
+collapse-by-target rule. `OrderDraftStore.add` enforces it:
+when the incoming command's `kind` is `"setProductionType"` it
+drops every prior `setProductionType` entry with the same
+`planetNumber` (and the matching keys from `statuses`) before
+appending. Other variants keep their append-only behaviour —
+each `planetRename` is a distinct user-visible action and
+collapsing them would lose intent.
+
+Net effect on the order tab: at most one `setProductionType`
+row per planet, regardless of how many times the player clicks
+through the inspector segments. Auto-sync still fires on every
+mutation; the engine accepts repeat submits idempotently. A
+`setProductionType` and a `planetRename` for the same planet
+coexist — the rules apply within a `kind`, not across.
+
 ## Store
 
 `OrderDraftStore` lives in