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/translator/helpers/claudeHelper.js

@@ -3,6 +3,7 @@ import { DEFAULT_THINKING_CLAUDE_SIGNATURE } from "../../config/defaultThinkingS
 import { adjustMaxTokens } from "./maxTokensHelper.js";
 import { applyCloaking } from "../../utils/claudeCloaking.js";
 import { deriveSessionId } from "../../utils/sessionManager.js";
+import { PROVIDERS } from "../../providers/index.js";
 
 // Check if message has valid non-empty content
 export function hasValidContent(msg) {
@@ -122,8 +123,6 @@ export function normalizeClaudePassthrough(body, model = "") {
   return body;
 }
 
-const CLAUDE_FORMAT_PROVIDERS_WITHOUT_OUTPUT_CONFIG = new Set(["minimax", "minimax-cn"]);
-
 // Prepare request for Claude format endpoints
 // - Cleanup cache_control
 // - Filter empty messages
@@ -131,9 +130,8 @@ const CLAUDE_FORMAT_PROVIDERS_WITHOUT_OUTPUT_CONFIG = new Set(["minimax", "minim
 // - Fix tool_use/tool_result ordering
 // - Apply cloaking (billing header + fake user ID) for OAuth tokens
 export function prepareClaudeRequest(body, provider = null, apiKey = null, connectionId = null) {
-  // MiniMax exposes a Claude-compatible endpoint but rejects Anthropic's extended
-  // structured output parameter with a generic 400 "invalid params" response.
-  if (CLAUDE_FORMAT_PROVIDERS_WITHOUT_OUTPUT_CONFIG.has(provider)) {
+  // quirk: MiniMax's Claude-compatible endpoint rejects Anthropic's output_config (400 invalid params)
+  if (PROVIDERS[provider]?.quirks?.dropOutputConfig) {
     delete body.output_config;
   }
 

open-sse/translator/helpers/imageHelper.js

@@ -3,6 +3,15 @@ export function encodeDataUri(mimeType, base64) {
   return `data:${mimeType};base64,${base64}`;
 }
 
+// Parse a base64 data URI → { mimeType, base64 }, or null if not a data URI.
+// [\s\S] tolerates newlines inside the base64 payload.
+const DATA_URI_RE = /^data:([^;]+);base64,([\s\S]+)$/;
+export function parseDataUri(url) {
+  if (typeof url !== "string") return null;
+  const m = url.match(DATA_URI_RE);
+  return m ? { mimeType: m[1], base64: m[2] } : null;
+}
+
 /**
  * Fetch a remote image URL and return it as a base64 data URI.
  * Used when upstream providers (Codex, etc.) require inline base64 images