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/opencodeProviderPresets.ts

@@ -1385,36 +1385,6 @@ export const opencodeProviderPresets: OpenCodeProviderPreset[] = [
       },
     },
   },
-  {
-    name: "AICoding",
-    websiteUrl: "https://aicoding.sh",
-    apiKeyUrl: "https://aicoding.sh/i/CCSWITCH",
-    settingsConfig: {
-      npm: "@ai-sdk/anthropic",
-      name: "AICoding",
-      options: {
-        baseURL: "https://api.aicoding.sh",
-        apiKey: "",
-        setCacheKey: true,
-      },
-      models: {
-        "claude-sonnet-4-6": { name: "Claude Sonnet 4.6" },
-        "claude-opus-4-7": { name: "Claude Opus 4.7" },
-      },
-    },
-    category: "third_party",
-    isPartner: true,
-    partnerPromotionKey: "aicoding",
-    icon: "aicoding",
-    iconColor: "#000000",
-    templateValues: {
-      apiKey: {
-        label: "API Key",
-        placeholder: "",
-        editorValue: "",
-      },
-    },
-  },
   {
     name: "CrazyRouter",
     websiteUrl: "https://www.crazyrouter.com",