chore: merge main into Bengali integration

Resolve the 3 conflicts from 104 upstream commits (2.2.1 -> 2.2.2).

Merge resolution:
- .claude-plugin/plugin.json, .claude-plugin/marketplace.json: take the
  upstream 2.2.2 version bump, keep the catalog counts at 69 agents /
  293 skills. Upstream released 2.2.2 still describing 68/292, so neither
  side could be taken whole.
- docs/ja-JP/README.md: upstream restructured the page, moving the hero
  above the fold and replacing both markdown language selectors with a
  single centered HTML block that also gained Español. Take that structure
  and re-add বাংলা to the new selector.
- rules/common/agents.md: merged clean, but the roster line main added
  reads "68 agents". Resync to 69 alongside the other catalog counts.

Verified: catalog.js reports 69 agents / 293 skills and confirms the
documentation counts match the repository catalog; the nine CI validators
and the command-registry check pass; bengali-language-surface.test.js is
7/7, including the selector and locale-parity assertions.

Co-Authored-By: Kishor Morol <kishormorol@gmail.com>

README.zh-CN.md

@@ -80,7 +80,7 @@
 
 ## 最新动态
 
-### v2.2.1 — 引导式多 Harness 安装（2026年8月）
+### v2.2.2 — 引导式多 Harness 安装（2026年8月）
 
 新增可审查的 Claude Code、Codex 与 Kimi Code 多 Harness 安装流程，并提供同步的 npm 命令入口。