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>

tests/__baseline__/providers-baseline.json

@@ -395,142 +395,8 @@
     "baseUrl": "https://token-plan-sgp.xiaomimimo.com/v1/chat/completions",
     "format": "openai"
   },
-  "agentrouter": {
-    "baseUrl": "https://agentrouter.org/v1/messages",
-    "format": "claude",
-    "headers": {
-      "Anthropic-Version": "2023-06-01",
-      "Anthropic-Beta": "claude-code-20250219,oauth-2025-04-20,interleaved-thinking-2025-05-14,context-management-2025-06-27,prompt-caching-scope-2026-01-05,advanced-tool-use-2025-11-20,effort-2025-11-24,structured-outputs-2025-12-15,fast-mode-2026-02-01,redact-thinking-2026-02-12,token-efficient-tools-2026-03-28",
-      "Anthropic-Dangerous-Direct-Browser-Access": "true",
-      "User-Agent": "claude-cli/2.1.92 (external, sdk-cli)",
-      "X-App": "cli",
-      "X-Stainless-Helper-Method": "stream",
-      "X-Stainless-Retry-Count": "0",
-      "X-Stainless-Runtime-Version": "v24.14.0",
-      "X-Stainless-Package-Version": "0.80.0",
-      "X-Stainless-Runtime": "node",
-      "X-Stainless-Lang": "js",
-      "X-Stainless-Arch": "arm64",
-      "X-Stainless-Os": "MacOS",
-      "X-Stainless-Timeout": "600"
-    }
-  },
-  "aimlapi": {
-    "baseUrl": "https://api.aimlapi.com/v1/chat/completions",
-    "format": "openai"
-  },
-  "novita": {
-    "baseUrl": "https://api.novita.ai/v3/openai/chat/completions",
-    "format": "openai"
-  },
-  "modal": {
-    "baseUrl": "https://api.modal.com/v1/chat/completions",
-    "format": "openai"
-  },
-  "reka": {
-    "baseUrl": "https://api.reka.ai/v1/chat/completions",
-    "format": "openai"
-  },
-  "nlpcloud": {
-    "baseUrl": "https://api.nlpcloud.io/v1/gpu/chatbot",
-    "format": "openai"
-  },
-  "bazaarlink": {
-    "baseUrl": "https://bazaarlink.ai/api/v1/chat/completions",
-    "format": "openai"
-  },
-  "completions": {
-    "baseUrl": "https://completions.me/api/v1/chat/completions",
-    "format": "openai"
-  },
-  "enally": {
-    "baseUrl": "https://ai.enally.in/v1/chat/completions",
-    "format": "openai",
-    "authHeader": "x-api-key"
-  },
-  "freetheai": {
-    "baseUrl": "https://api.freetheai.xyz/v1/chat/completions",
-    "format": "openai"
-  },
-  "llm7": {
-    "baseUrl": "https://api.llm7.io/v1/chat/completions",
-    "format": "openai"
-  },
-  "lepton": {
-    "baseUrl": "https://api.lepton.ai/api/v1/chat/completions",
-    "format": "openai"
-  },
-  "kluster": {
-    "baseUrl": "https://api.kluster.ai/v1/chat/completions",
-    "format": "openai"
-  },
-  "ai21": {
-    "baseUrl": "https://api.ai21.com/studio/v1/chat/completions",
-    "format": "openai"
-  },
-  "inference-net": {
-    "baseUrl": "https://api.inference.net/v1/chat/completions",
-    "format": "openai"
-  },
-  "predibase": {
-    "baseUrl": "https://serving.app.predibase.com/v1/chat/completions",
-    "format": "openai"
-  },
-  "bytez": {
-    "baseUrl": "https://api.bytez.com/models/v2",
-    "format": "openai"
-  },
-  "morph": {
-    "baseUrl": "https://api.morphllm.com/v1/chat/completions",
-    "format": "openai"
-  },
-  "longcat": {
-    "baseUrl": "https://api.longcat.chat/openai/v1/chat/completions",
-    "format": "openai"
-  },
-  "puter": {
-    "baseUrl": "https://api.puter.com/puterai/openai/v1/chat/completions",
-    "format": "openai"
-  },
-  "uncloseai": {
-    "baseUrl": "https://hermes.ai.unturf.com/v1/chat/completions",
-    "format": "openai",
-    "noAuth": true
-  },
-  "scaleway": {
-    "baseUrl": "https://api.scaleway.ai/v1/chat/completions",
-    "format": "openai"
-  },
-  "deepinfra": {
-    "baseUrl": "https://api.deepinfra.com/v1/openai/chat/completions",
-    "format": "openai"
-  },
-  "sambanova": {
-    "baseUrl": "https://api.sambanova.ai/v1/chat/completions",
-    "format": "openai"
-  },
-  "nscale": {
-    "baseUrl": "https://inference.api.nscale.com/v1/chat/completions",
-    "format": "openai"
-  },
-  "baseten": {
-    "baseUrl": "https://inference.baseten.co/v1/chat/completions",
-    "format": "openai"
-  },
-  "publicai": {
-    "baseUrl": "https://api.publicai.co/v1/chat/completions",
-    "format": "openai"
-  },
-  "nous-research": {
-    "baseUrl": "https://inference-api.nousresearch.com/v1/chat/completions",
-    "format": "openai"
-  },
-  "glhf": {
-    "baseUrl": "https://glhf.chat/api/openai/v1/chat/completions",
-    "format": "openai"
-  },
   "blackbox": {
     "baseUrl": "https://api.blackbox.ai/chat/completions",
     "format": "openai"
   }
-}
+}