fix: draw street map ground and repair mobile layout

- Turn the satellite ground off behind SATELLITE_GROUND so OSM streets,
  parks and land use are drawn; the imagery index is no longer fetched.
- Restore phone rules lost in the CSS-to-JS theme migration (#rank
  height, toolbar button size) and replace invalid -var() values.
- Add a landscape-phone layout and make the briefing scrollable.
- Add two-finger pinch zoom to the big map.
- Add regression tests for the theme and the skipped imagery request.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/services/worldService.js

@@ -1,4 +1,5 @@
 import { apiClient } from './apiClient.js';
+import { SATELLITE_GROUND } from '../constants/world.js';
 const WORLD_FILES = {
   buildings: './data/buildings.bin',
   imagery: './imagery/index.json',
@@ -6,7 +7,7 @@ const WORLD_FILES = {
 
 /** Loads optional world assets without preventing the OSM fallback on network failure.
  * @param {AbortSignal} signal - Cancels startup when the game unmounts.
- * @returns {Promise<Array>} Binary buildings and imagery index, or null fallbacks.
+ * @returns {Promise<Array>} Binary buildings and imagery index (null while SATELLITE_GROUND is off), or null fallbacks.
  */
 export async function loadWorldFiles(signal) {
   const requests = [
@@ -14,9 +15,12 @@ export async function loadWorldFiles(signal) {
       responseType: 'arraybuffer',
       signal,
     }),
-    apiClient.get(WORLD_FILES.imagery, {
-      signal,
-    }),
+    // Without the satellite ground the tile index is not needed, so it is not downloaded.
+    SATELLITE_GROUND
+      ? apiClient.get(WORLD_FILES.imagery, {
+          signal,
+        })
+      : Promise.resolve({ data: null }),
   ];
   const results = await Promise.allSettled(requests);
   return results.map((result) => (result.status === 'fulfilled' ? result.value.data : null));