chore(sponsors): drop AICoding partner from README, presets and i18n

Remove AICoding (aicoding.sh) sponsor entry from the three README files
and the provider preset across all seven app_types (claude, codex,
gemini, hermes, opencode, openclaw, claudeDesktop). Also drop the
matching partner_promotion.aicoding string in zh/en/ja locales.

The icon (src/icons/extracted/index.ts) and the legacy provider id in
codex_history_migration.rs are kept intentionally: the former for
possible later re-use, the latter so existing users' Codex history
still gets bucketed into "custom" on upgrade.

src/config/geminiProviderPresets.ts

@@ -159,26 +159,6 @@ export const geminiProviderPresets: GeminiProviderPreset[] = [
     icon: "aicodemirror",
     iconColor: "#000000",
   },
-  {
-    name: "AICoding",
-    websiteUrl: "https://aicoding.sh",
-    apiKeyUrl: "https://aicoding.sh/i/CCSWITCH",
-    settingsConfig: {
-      env: {
-        GOOGLE_GEMINI_BASE_URL: "https://api.aicoding.sh",
-        GEMINI_MODEL: "gemini-3.1-pro",
-      },
-    },
-    baseURL: "https://api.aicoding.sh",
-    model: "gemini-3.1-pro",
-    description: "AICoding",
-    category: "third_party",
-    isPartner: true,
-    partnerPromotionKey: "aicoding",
-    endpointCandidates: ["https://api.aicoding.sh"],
-    icon: "aicoding",
-    iconColor: "#000000",
-  },
   {
     name: "CrazyRouter",
     websiteUrl: "https://www.crazyrouter.com",