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)

src/icons/extracted/metadata.ts

@@ -225,6 +225,22 @@ export const iconMetadata: Record<string, IconMetadata> = {
     keywords: ["etok", "ai", "programming"],
     defaultColor: "#F97316",
   },
+  fenno: {
+    name: "fenno",
+    displayName: "FennoAI",
+    category: "ai-provider",
+    keywords: [
+      "fenno",
+      "fennoai",
+      "aggregator",
+      "relay",
+      "claude",
+      "codex",
+      "gpt",
+      "gateway",
+    ],
+    defaultColor: "#000000",
+  },
   cubence: {
     name: "cubence",
     displayName: "Cubence",