feat(ui): F8-11 — battles table under table submenu (#54)

Adds a sortable battles list as a new entity under the existing
`view → table` submenu (entity slug `battles`), replacing the
standalone top-level `battle log` shortcut which always opened a
"battle not found" placeholder. The single-battle viewer stays put
and is reached only by clicking a row (or a battle marker on the
map), identical to the existing `section-battles.svelte` flow.

Columns are planet (via the shared `planetLabel` helper) and shots
(the per-battle action count carried by `BattleSummary`), sortable
both ways with shots-desc default. No backend / FBS / map changes:
the wire payload is unchanged. Participants / observers / total
mass require the full BattleReport and were intentionally dropped
to avoid N round trips per menu open.

The top-level `battle log` item is removed from `header/view-menu`
and `sidebar/bottom-tabs` (and their stale comment blocks updated);
the now-orphan `game.view.battle` i18n key is dropped from both
locales.

ui/frontend/tests/e2e/game-shell.spec.ts

@@ -63,7 +63,6 @@ test("header view-menu navigates to every active view", async ({ page }) => {
 	const destinations: Array<[string, string]> = [
 		["view-menu-item-report", "active-view-report"],
 		["view-menu-item-mail", "active-view-mail"],
-		["view-menu-item-battle", "active-view-battle"],
 		["view-menu-item-designer-science", "active-view-designer-science"],
 		["view-menu-item-map", "active-view-map"],
 	];
@@ -86,6 +85,7 @@ test("header view-menu Tables sub-list navigates to every entity", async ({
 		"fleets",
 		"sciences",
 		"races",
+		"battles",
 	];
 	for (const entity of entities) {
 		await page.getByTestId("view-menu-trigger").click();