feat(presets): add FennoAI provider preset for 6 apps

Add FennoAI (api.fenno.ai) as a partner aggregator preset across Claude
Code, Claude Desktop, Codex, OpenCode, OpenClaw, and Hermes (Gemini not
supported). FennoAI relays native Claude/GPT, so Claude Code/Codex pass
through native models; the OpenAI-compatible apps default to gpt-5.5.

- Claude / Claude Desktop: Anthropic-compatible bare host (api.fenno.ai)
- Codex: native Responses at api.fenno.ai, gpt-5.5
- OpenCode / OpenClaw / Hermes: gpt-5.5 over api.fenno.ai/v1
- Partner referral link as apiKeyUrl + short partner-promotion blurb in
  zh/en/ja/zh-TW
- Add FennoAI sponsor entry to all four READMEs (fenno-banner.png)
- Register fenno-icon.webp icon (URL import + iconUrls + metadata)

README_ZH.md

@@ -151,6 +151,11 @@ Claude Code / Codex / Gemini 官方渠道低至 3.8 / 0.2 / 0.9 折，充值更
 <td>感谢 Unity2.ai 赞助了本项目！Unity2.ai 是面向个人开发者、团队和企业的高性能 AI 模型 API 中转平台，长期服务国内头部企业，日均承载超 300 亿 token 调用，支持 5000 RPM 级高并发。支持余额计费、首充赠额、组合订阅、企业开票和专属对接。通过<a href="https://unity2.ai/register?source=ccs">此链接</a>注册可领取 $2 余额，加入官方群再送 $10 余额，最高可领 $12 免费额度！</td>
 </tr>
 
+<tr>
+<td width="180"><a href="https://api.fenno.ai/register?redirect=/purchase?tab=subscription%26group=16&aff=P9MR3D3PLCNL"><img src="assets/partners/logos/fenno-banner.png" alt="Fenno.ai" width="150"></a></td>
+<td>感谢 Fenno.ai 赞助了本项目！Fenno.ai 是一家稳定、高效的 API 中转服务商，目前主要提供 Codex 中转服务，兼容 OpenAI 及 Anthropic 协议，可灵活接入 Codex、Claude Code、OpenCode 等主流编程工具，可稳定支撑千亿 Token/日的企业级调用需求，支持国内及海外主体公对公结算、开票。Fenno.ai 为 CC Switch 的用户提供了专属福利：通过<a href="https://api.fenno.ai/register?redirect=/purchase?tab=subscription%26group=16&aff=P9MR3D3PLCNL">此链接</a>即可订阅 9.9 元/150 刀额度的超值 Coding Plan，邀请好友最高可享 20% 奖励，多邀多得！</td>
+</tr>
+
 </table>
 
 </details>