fix(image): prevent compatible nodes from shadowing provider aliases

Build a reserved prefix set from registry provider ids/aliases plus local
aliases, and skip compatible-node prefix matching for reserved prefixes so
built-in routes like cf/... stay on Cloudflare.

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

tests/unit/model-routing.test.js

@@ -0,0 +1,80 @@
+import fs from "node:fs";
+import os from "node:os";
+import path from "node:path";
+import { describe, it, expect, beforeEach, afterEach, vi } from "vitest";
+
+const originalDataDir = process.env.DATA_DIR;
+
+async function setupDb() {
+  const tempDir = fs.mkdtempSync(path.join(os.tmpdir(), "9router-model-routing-"));
+  process.env.DATA_DIR = tempDir;
+  vi.resetModules();
+
+  const { createProviderNode } = await import("@/models/index.js");
+  const { getModelInfo } = await import("@/sse/services/model.js");
+
+  return {
+    createProviderNode,
+    getModelInfo,
+    cleanup() {
+      fs.rmSync(tempDir, { recursive: true, force: true });
+    },
+  };
+}
+
+describe("model routing", () => {
+  let cleanup = () => {};
+
+  beforeEach(() => {
+    vi.clearAllMocks();
+  });
+
+  afterEach(() => {
+    vi.resetModules();
+    vi.clearAllMocks();
+    cleanup();
+    cleanup = () => {};
+    if (originalDataDir === undefined) delete process.env.DATA_DIR;
+    else process.env.DATA_DIR = originalDataDir;
+  });
+
+  it("keeps built-in provider aliases ahead of compatible node prefixes", async () => {
+    const ctx = await setupDb();
+    cleanup = ctx.cleanup;
+
+    await ctx.createProviderNode({
+      id: "openai-compatible-chat-test",
+      type: "openai-compatible",
+      name: "Compatible CF Collision",
+      prefix: "cf",
+      apiType: "chat",
+      baseUrl: "https://compatible.test/v1",
+    });
+
+    await expect(ctx.getModelInfo("cf/@cf/black-forest-labs/flux-2-klein-9b"))
+      .resolves.toEqual({
+        provider: "cloudflare-ai",
+        model: "@cf/black-forest-labs/flux-2-klein-9b",
+      });
+  });
+
+  it("still routes non-reserved compatible node prefixes", async () => {
+    const ctx = await setupDb();
+    cleanup = ctx.cleanup;
+
+    await ctx.createProviderNode({
+      id: "openai-compatible-chat-test",
+      type: "openai-compatible",
+      name: "Compatible OCT",
+      prefix: "oct",
+      apiType: "chat",
+      baseUrl: "https://compatible.test/v1",
+    });
+
+    await expect(ctx.getModelInfo("oct/gpt-image-1"))
+      .resolves.toEqual({
+        provider: "openai-compatible-chat-test",
+        model: "gpt-image-1",
+      });
+  });
+});