feat(phase1): rebrand to TTRPG Player and drop Git updates feed

Rename product to TTRPG Player (TTRPGPlayer / com.ttrpgplayer.app), use .ttrpg.zip for new saves while keeping .dnd.zip import, accept TTRPG- and DND- license keys on client, and remove sync-update-feed plus CI push to DndGamePlayerUpdates.

Co-authored-by: Cursor <cursoragent@cursor.com>

app/shared/package.build.test.ts

@@ -20,7 +20,7 @@ void test('package.json: конфиг electron-builder (mac/win/linux)', () => {
     };
   };
   assert.ok(pkg.build);
-  assert.equal(pkg.build.appId, 'com.dndplayer.app');
+  assert.equal(pkg.build.appId, 'com.ttrpgplayer.app');
   assert.equal(pkg.build.asar, true, 'релизный артефакт: app.asar без «голого» дерева dist в .app/.exe');
   assert.ok(Array.isArray(pkg.build.asarUnpack));
   assert.ok(pkg.build.asarUnpack.some((p) => p.includes('preload')));