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/renderer/editor/EditorApp.tsx

@@ -4,6 +4,7 @@ import { createPortal } from 'react-dom';
 import { ipcChannels, type UpdaterCheckResponse } from '../../shared/ipc/contracts';
 import { EULA_CURRENT_VERSION } from '../../shared/license/eulaVersion';
 import type { LicenseSnapshot } from '../../shared/license/licenseSnapshot';
+import { PROJECT_ZIP_EXTENSION } from '../../shared/project/projectZipExtension';
 import type { AssetId, MediaAsset, Project, ProjectId, SceneAudioRef, SceneId } from '../../shared/types';
 import { AppLogo } from '../shared/branding/AppLogo';
 import { getDndApi } from '../shared/dndApi';
@@ -377,7 +378,7 @@ export function EditorApp() {
               title={t('top.backToProjects')}
             >
               <AppLogo className={styles.brandLogo} size={26} />
-              <div className={styles.brandTitle}>DNDGamePlayer</div>
+              <div className={styles.brandTitle}>{t('app.brandTitle')}</div>
             </button>
             <div className={styles.fileToolbar}>
               <button
@@ -1319,7 +1320,7 @@ function RenameProjectModal({
             <div className={styles.flex1}>
               <Input value={fileBaseName} onChange={setFileBaseName} placeholder="my_campaign" />
             </div>
-            <div className={styles.fileSuffix}>.dnd.zip</div>
+            <div className={styles.fileSuffix}>{PROJECT_ZIP_EXTENSION}</div>
           </div>
           {!fileNameOk ? <div className={styles.fieldError}>{t('rename.fileInvalid')}</div> : null}
           {fileNameDup ? <div className={styles.fieldError}>{t('rename.fileDup')}</div> : null}