feat(ui): F8-12 — map polish (zoom invariance, labels, selection, soft radius) (#55)

* Honest pixel-space sizing for `pointRadiusPx` / `strokeWidthPx`: the
  renderer divides by the current camera scale on every
  `viewport.zoomed` so thin lines / small markers stay the same on-screen
  size at any zoom.
* Known-size planets switch to `pointRadiusWorld`, softened against the
  reference scale by `PLANET_SIZE_ZOOM_ALPHA = 0.33`; unidentified
  planets pin to a 3-px disc.
* New planet label layer renders a two-line `name / #N` legend under
  each planet (`#N` only for unidentified or when the new `planetNames`
  toggle is off). Selection now paints an inverse-fill frame around the
  selected planet's label plus an outline on the disc; the old
  selection-ring primitive is retired.
* Bombing markers swap the separate CirclePrim for a planet-outline
  overlay (damaged / wiped colour); the report deep-link moves to a
  "view bombing report" link in the planet inspector.
* Docs + tests follow: `renderer.md` reflects the new sizing contract +
  label / outline layers, vitest covers the sizing math, label
  formatting, and the new toggle, and the map-toggles e2e adds a
  persistence case for `planetNames`.

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

ui/frontend/tests/map-toggles-state.test.ts

@@ -113,6 +113,7 @@ describe("GameStateStore.mapToggles persistence", () => {
 		await a.init({ client: makeFakeClient(3), cache, gameId: GAME_ID });
 		await a.setMapToggle("hyperspaceGroups", false);
 		await a.setMapToggle("battleMarkers", false);
+		await a.setMapToggle("planetNames", false);
 		await a.setMapToggle("visibleHyperspace", false);
 		a.dispose();
 
@@ -121,6 +122,7 @@ describe("GameStateStore.mapToggles persistence", () => {
 		await b.init({ client: makeFakeClient(3), cache, gameId: GAME_ID });
 		expect(b.mapToggles.hyperspaceGroups).toBe(false);
 		expect(b.mapToggles.battleMarkers).toBe(false);
+		expect(b.mapToggles.planetNames).toBe(false);
 		expect(b.mapToggles.visibleHyperspace).toBe(false);
 		// Untouched flags retain defaults.
 		expect(b.mapToggles.bombingMarkers).toBe(true);
@@ -141,6 +143,7 @@ describe("GameStateStore.mapToggles persistence", () => {
 		expect(store.mapToggles.hyperspaceGroups).toBe(false);
 		expect(store.mapToggles.battleMarkers).toBe(true);
 		expect(store.mapToggles.bombingMarkers).toBe(true);
+		expect(store.mapToggles.planetNames).toBe(true);
 		expect(store.mapToggles.visibleHyperspace).toBe(true);
 		store.dispose();
 	});