ui/phase-19: read-only ship-group inspector + sheet + tab dispatch

Closes Phase 19's UI surface. The inspector dispatches on the
selection variant: local / other groups render class, count, the
four tech levels, mass, cargo (type + amount when loaded),
location (planet name on-orbit, from/to/distance in hyperspace),
and — for local groups only — fleet membership + state. Incoming
groups surface origin / destination / distance / speed and the
inline ETA = ceil(distance / speed); zero speed collapses to the
designer's existing "—" placeholder. Unidentified groups render
just the (x, y) coordinates and the no-data hint, mirroring the
unidentified planet treatment.

Layout / inspector-tab plumbing:
  - inspector-tab.svelte derives selectedShipGroup against the
    rendered report and mounts <ShipGroup /> when the planet
    branch doesn't match. Stale refs (an index that no longer
    resolves after a turn refresh) collapse cleanly to the empty
    state.
  - +layout.svelte mounts <ShipGroupSheet /> alongside the
    existing planet sheet on mobile; both share the
    `effectiveTool === "map"` guard and clear-on-close.

i18n: en + ru both grow ~30 keys under
`game.inspector.ship_group.*`. Adding a key to one without the
other is a TS error (TranslationKey is `keyof typeof en`), so the
Russian mirror stays mandatory.

Tests:
  - inspector-ship-group.test.ts exercises every variant —
    on-planet local, in-hyperspace local, cargo-loaded local,
    foreign, incoming with ETA, incoming with zero speed,
    unidentified, plus the missing-planet `#NN` fallback.
  - tests/e2e/inspector-ship-group.spec.ts is a smoke spec that
    drives the DEV-only synthetic-report loader from /lobby
    through navigation to /games/synthetic-XXX/map.

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

ui/frontend/tests/e2e/inspector-ship-group.spec.ts

@@ -0,0 +1,134 @@
+// Phase 19 end-to-end smoke against the synthetic-report path. Loads
+// a hand-crafted JSON with a Tancordia-style mix of planets and ship
+// groups through the DEV-only file picker on `/lobby`, lets the
+// in-game shell layout swap into synthetic mode, and asserts the map
+// canvas mounts. Detailed click / hit-test fidelity for ship-group
+// variants lives in the unit tests (`tests/state-binding-groups.test.ts`
+// and `tests/inspector-ship-group.test.ts`); this spec catches the
+// glue: lobby loader → in-memory registry → layout bypass → renderer
+// boot.
+
+import { expect, test } from "@playwright/test";
+
+const SYNTHETIC_REPORT_FIXTURE = {
+	turn: 39,
+	mapWidth: 200,
+	mapHeight: 200,
+	mapPlanets: 4,
+	race: "Earthlings",
+	player: [
+		{
+			name: "Earthlings",
+			drive: 5,
+			weapons: 3,
+			shields: 2,
+			cargo: 1,
+			population: 1000,
+			industry: 1000,
+			planets: 2,
+			relation: "-",
+			votes: 5,
+			extinct: false,
+		},
+	],
+	localPlanet: [
+		{
+			number: 1,
+			name: "Earth",
+			x: 50,
+			y: 100,
+			size: 1000,
+			population: 1000,
+			industry: 1000,
+			resources: 10,
+			production: "Capital",
+			capital: 0,
+			material: 0,
+			colonists: 100,
+			freeIndustry: 1000,
+		},
+		{
+			number: 2,
+			name: "Mars",
+			x: 150,
+			y: 100,
+			size: 500,
+			population: 500,
+			industry: 500,
+			resources: 5,
+			production: "Capital",
+			capital: 0,
+			material: 0,
+			colonists: 50,
+			freeIndustry: 500,
+		},
+	],
+	otherPlanet: [],
+	uninhabitedPlanet: [],
+	unidentifiedPlanet: [
+		{ number: 3, x: 50, y: 50 },
+		{ number: 4, x: 150, y: 50 },
+	],
+	localShipClass: [
+		{
+			name: "Frontier",
+			drive: 5,
+			armament: 0,
+			weapons: 0,
+			shields: 0,
+			cargo: 1,
+			mass: 12,
+		},
+	],
+	localGroup: [
+		{
+			id: "11111111-2222-3333-4444-555555555555",
+			number: 2,
+			class: "Frontier",
+			tech: { drive: 5, weapons: 0, shields: 0, cargo: 1 },
+			cargo: "-",
+			load: 0,
+			destination: 1,
+			speed: 0,
+			mass: 12,
+			state: "In_Orbit",
+		},
+	],
+	otherGroup: [],
+	incomingGroup: [
+		{
+			origin: 4,
+			destination: 1,
+			distance: 50,
+			speed: 25,
+			mass: 4,
+		},
+	],
+	unidentifiedGroup: [],
+	localFleet: [],
+};
+
+test("synthetic-report loader navigates from lobby to map and renders", async ({
+	page,
+}) => {
+	await page.goto("/lobby");
+	await expect(page.getByTestId("lobby-synthetic-section")).toBeVisible();
+
+	const file = page.getByTestId("lobby-synthetic-file");
+	await file.setInputFiles({
+		name: "phase19.json",
+		mimeType: "application/json",
+		buffer: Buffer.from(JSON.stringify(SYNTHETIC_REPORT_FIXTURE)),
+	});
+
+	await page.waitForURL(/\/games\/synthetic-[^/]+\/map$/, {
+		timeout: 5_000,
+	});
+
+	// The renderer canvas mounts inside the active-view host. Even if
+	// the WebGL/WebGPU backend is unavailable in CI, the layout still
+	// reaches `ready` once the report is loaded — the assertion is
+	// gentle on purpose so the spec doesn't flake on headless renders.
+	const canvas = page.locator("canvas");
+	await expect(canvas.first()).toBeVisible({ timeout: 10_000 });
+});