0.2.6-dev: merge claude/bw-l01 — host bandwidth layers 0 and 1 (no BGM download while the music is silent, WebSocket permessage-deflate, lossless WebP 玩法说明 pages, traffic counters, content-hashed asset URLs with immutable caching, brotli q5) on top of the 0.2.5 release; its note becomes DESIGN §31 in docs/history/0.2.6.md, CHANGELOG 0.2.6-dev, version 0.2.6-dev; golden: unchanged

shared/constants.js

@@ -5,7 +5,7 @@ import { N_ } from './i18n.js';
 export const PROTOCOL_VERSION = 1;
 /** Release version shown to players (title screen, server banner, /healthz). Kept equal to package.json "version"
  * (test/version.test.js); PROTOCOL_VERSION above is the separate wire-format number. */
-export const APP_VERSION = '0.2.5';
+export const APP_VERSION = '0.2.6-dev';
 /** A development build (the public `dev` branch): the title screen, the boot banner and the README say so, and
  * tools/package.mjs refuses to build a release zip from it without --allow-dev. */
 export const DEV_BUILD = /-dev$/.test(APP_VERSION);