refactor(open-sse): registry consolidation + DRY media/oauth/adhoc cleanup

- Single-source registry: oauth clientId/tokenUrl, usage URLs, image/embed
  configs, search defaultModel, codex fixedPort, google token url derive.
- Remove 29 unused OmniRoute providers (registry 100→71); media intact.
- De-adhoc: codex literals → registry format/oauth flags; reasoningInject,
  image/embed openrouter headers + xai bodyFields config-driven.
- Add REGISTRY_TEMPLATE.js + expand PROVIDER_DEFAULTS/schema JSDoc.
- Baselines updated; PROVIDERS 62 + alias 90 byte-for-byte, golden snapshots.

Co-authored-by: Cursor <cursoragent@cursor.com>

open-sse/providers/registry/antigravity.js

@@ -4,6 +4,19 @@ import { ANTIGRAVITY_OAUTH_CLIENT } from "../shared.js";
 export default {
   id: "antigravity",
   alias: "ag",
+  display: {
+      "name": "Antigravity",
+      "icon": "rocket_launch",
+      "color": "#F59E0B",
+      "website": "https://antigravity.google",
+      "notice": {
+          "signupUrl": "https://antigravity.google"
+      },
+      "deprecated": true,
+      "deprecationNotice": "RISK_NOTICE"
+  },
+  category: "oauth",
+  uiAlias: "ag",
   transport: {
     baseUrls: [
       "https://daily-cloudcode-pa.googleapis.com",
@@ -11,8 +24,35 @@ export default {
     ],
     format: "antigravity",
     headers: { "User-Agent": `antigravity/1.107.0 ${platform()}/${arch()}` },
+    // 429/503 use computeRetryDelay hook (Retry-After header/body → cap, else backoff)
+    retry: { 429: { attempts: 6 }, 503: { attempts: 3 } },
+    usage: {
+      quotaApiUrl: "https://cloudcode-pa.googleapis.com/v1internal:fetchAvailableModels",
+      loadProjectApiUrl: "https://cloudcode-pa.googleapis.com/v1internal:loadCodeAssist",
+      tokenUrl: "https://oauth2.googleapis.com/token"
+    },
     ...ANTIGRAVITY_OAUTH_CLIENT
   },
+  oauth: {
+    authorizeUrl: "https://accounts.google.com/o/oauth2/v2/auth",
+    tokenUrl: "https://oauth2.googleapis.com/token",
+    userInfoUrl: "https://www.googleapis.com/oauth2/v1/userinfo",
+    scopes: [
+      "https://www.googleapis.com/auth/cloud-platform",
+      "https://www.googleapis.com/auth/userinfo.email",
+      "https://www.googleapis.com/auth/userinfo.profile",
+      "https://www.googleapis.com/auth/cclog",
+      "https://www.googleapis.com/auth/experimentsandconfigs"
+    ],
+    apiEndpoint: "https://cloudcode-pa.googleapis.com",
+    apiVersion: "v1internal",
+    loadCodeAssistEndpoint: "https://cloudcode-pa.googleapis.com/v1internal:loadCodeAssist",
+    onboardUserEndpoint: "https://cloudcode-pa.googleapis.com/v1internal:onboardUser",
+    loadCodeAssistUserAgent: "google-api-nodejs-client/9.15.1",
+    loadCodeAssistApiClient: "google-cloud-sdk vscode_cloudshelleditor/0.1"
+  ,
+    refreshLeadMs: 300000
+  },
   models: [
     { id: "gemini-3-flash-agent", name: "Gemini 3.5 Flash (High)" },
     { id: "gemini-3.5-flash-low", name: "Gemini 3.5 Flash (Medium)" },
@@ -23,5 +63,6 @@ export default {
     { id: "claude-opus-4-6-thinking", name: "Claude Opus 4.6 (Thinking)" },
     { id: "gpt-oss-120b-medium", name: "GPT-OSS 120B (Medium)" },
     { id: "gemini-3-flash", name: "Gemini 3 Flash", thinking: false }
-  ]
+  ],
+  features: {"usage":true},
 };