feat(ui): F8-10 — tables planets / ship-groups / fleets, ship-classes delete guard (#53)

Lights up three previously-stubbed table active views and tightens the
existing one:

  - table-planets: 4 kind checkboxes (own / foreign / uninhabited /
    unknown) + race dropdown that filters the foreign slice; row click
    selects + centres the planet on the map.
  - table-ship-groups: local + foreign groups in one grid, owner
    checkboxes, planet dropdown (destination OR origin), class
    dropdown; on-planet click focuses the destination planet, in-space
    click focuses the ship group itself (camera follows interpolated
    position).
  - table-fleets: own fleets only with the shared planet dropdown;
    on-planet click focuses the planet, in-space click centres the
    camera on the interpolated fleet position without altering the
    selection (no fleet variant in Selected).
  - table-ship-classes: per-row Delete is disabled with a count tooltip
    while at least one local ship group references the class. The
    engine refuses the removal anyway; the UI pre-empts the surface.

Wires the click → map flow through a transient `SelectionStore.focus`
/ `focusPoint` channel that `map.svelte` consumes once on mount —
in-memory only, so an F5 does not re-centre.

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

ui/frontend/tests/selection-store.test.ts

@@ -44,4 +44,89 @@ describe("SelectionStore", () => {
 		store.clear();
 		expect(store.selected).toBeNull();
 	});
+
+	test("focus sets the selection and queues the pending focus", () => {
+		const store = new SelectionStore();
+		store.focus({ kind: "planet", id: 11 });
+		expect(store.selected).toEqual({ kind: "planet", id: 11 });
+		expect(store.consumePendingFocus()).toEqual({ kind: "planet", id: 11 });
+	});
+
+	test("focus also works for a ship group target", () => {
+		const store = new SelectionStore();
+		store.focus({ kind: "shipGroup", ref: { variant: "local", id: "abc" } });
+		expect(store.selected).toEqual({
+			kind: "shipGroup",
+			ref: { variant: "local", id: "abc" },
+		});
+		expect(store.consumePendingFocus()).toEqual({
+			kind: "shipGroup",
+			ref: { variant: "local", id: "abc" },
+		});
+	});
+
+	test("consumePendingFocus clears the queued request", () => {
+		const store = new SelectionStore();
+		store.focus({ kind: "planet", id: 1 });
+		expect(store.consumePendingFocus()).not.toBeNull();
+		expect(store.consumePendingFocus()).toBeNull();
+	});
+
+	test("consumePendingFocus returns null when no focus was queued", () => {
+		const store = new SelectionStore();
+		store.selectPlanet(5);
+		expect(store.consumePendingFocus()).toBeNull();
+	});
+
+	test("clear leaves any queued pending focus untouched", () => {
+		const store = new SelectionStore();
+		store.focus({ kind: "planet", id: 9 });
+		store.clear();
+		expect(store.selected).toBeNull();
+		expect(store.consumePendingFocus()).toEqual({ kind: "planet", id: 9 });
+	});
+
+	test("dispose drops a queued pending focus", () => {
+		const store = new SelectionStore();
+		store.focus({ kind: "planet", id: 2 });
+		store.dispose();
+		expect(store.consumePendingFocus()).toBeNull();
+	});
+
+	test("focus is a no-op after dispose", () => {
+		const store = new SelectionStore();
+		store.dispose();
+		store.focus({ kind: "planet", id: 7 });
+		expect(store.selected).toBeNull();
+		expect(store.consumePendingFocus()).toBeNull();
+	});
+
+	test("focusPoint queues a coord without touching selection", () => {
+		const store = new SelectionStore();
+		store.selectPlanet(1);
+		store.focusPoint(12, 34);
+		expect(store.selected).toEqual({ kind: "planet", id: 1 });
+		expect(store.consumePendingCenter()).toEqual({ x: 12, y: 34 });
+	});
+
+	test("consumePendingCenter clears the queued point", () => {
+		const store = new SelectionStore();
+		store.focusPoint(5, 7);
+		expect(store.consumePendingCenter()).toEqual({ x: 5, y: 7 });
+		expect(store.consumePendingCenter()).toBeNull();
+	});
+
+	test("dispose drops a queued pending centre", () => {
+		const store = new SelectionStore();
+		store.focusPoint(1, 2);
+		store.dispose();
+		expect(store.consumePendingCenter()).toBeNull();
+	});
+
+	test("focusPoint is a no-op after dispose", () => {
+		const store = new SelectionStore();
+		store.dispose();
+		store.focusPoint(1, 2);
+		expect(store.consumePendingCenter()).toBeNull();
+	});
 });