feat(providers): add four OpenAI-compatible aggregator providers (dahl, atria, agnes, bai)

Adds Dahl Inference, Atria Dawn, Agnes AI, and B.AI following the existing
registry pattern. Each uses DefaultExecutor with no custom translator needed.

tests/unit/aggregator-providers-batch.test.js

@@ -0,0 +1,137 @@
+import { describe, expect, it } from "vitest";
+import { existsSync, readFileSync } from "node:fs";
+import { fileURLToPath } from "node:url";
+import { dirname, join } from "node:path";
+
+import REGISTRY from "../../open-sse/providers/registry/index.js";
+import { PROVIDERS } from "../../open-sse/providers/index.js";
+import { getExecutor } from "../../open-sse/executors/index.js";
+import { DefaultExecutor } from "../../open-sse/executors/default.js";
+
+/**
+ * OpenAI-compatible aggregator providers. Each was verified by probing the
+ * live /v1/models endpoint: a 401 with a structured error body confirms a
+ * real API behind the host, and Dahl/Kira answer 200 with no credentials.
+ */
+const BATCH = [
+  {
+    id: "dahl",
+    category: "apikey",
+    baseUrl: "https://inference.dahl.global/v1/chat/completions",
+    modelsUrl: "https://inference.dahl.global/v1/models",
+    aliases: ["dahl-inference"],
+  },
+  {
+    id: "atria",
+    category: "apikey",
+    baseUrl: "https://api.atria-asi.ai/v1/chat/completions",
+    modelsUrl: "https://api.atria-asi.ai/v1/models",
+    aliases: ["atria-asi"],
+  },
+  {
+    id: "agnes",
+    category: "freeTier",
+    baseUrl: "https://apihub.agnes-ai.com/v1/chat/completions",
+    modelsUrl: "https://apihub.agnes-ai.com/v1/models",
+    aliases: ["agnes-ai"],
+  },
+  {
+    id: "bai",
+    category: "apikey",
+    baseUrl: "https://api.b.ai/v1/chat/completions",
+    modelsUrl: "https://api.b.ai/v1/models",
+    aliases: ["b-ai"],
+  },
+];
+
+describe.each(BATCH)("$id provider", (p) => {
+  const entry = REGISTRY.find((e) => e.id === p.id);
+
+  it("is registered with the expected category and base URL", () => {
+    expect(entry).toBeDefined();
+    expect(entry.category).toBe(p.category);
+    expect(PROVIDERS[p.id].baseUrl).toBe(p.baseUrl);
+    expect(PROVIDERS[p.id].format).toBe("openai");
+  });
+
+  it("exposes its aliases and a UI display name", () => {
+    for (const a of p.aliases) expect(entry.aliases).toContain(a);
+    expect(entry.display?.name).toBeTruthy();
+    expect(entry.display?.textIcon).toBeTruthy();
+  });
+
+  it("routes through the shared DefaultExecutor", () => {
+    expect(getExecutor(p.id)).toBeInstanceOf(DefaultExecutor);
+  });
+
+  it("accepts arbitrary model ids via passthrough", () => {
+    expect(entry.passthroughModels).toBe(true);
+  });
+});
+
+describe("Atria Dawn specifics", () => {
+  const entry = REGISTRY.find((e) => e.id === "atria");
+
+  it("is named after the service, not just the host", () => {
+    expect(entry.display.name).toBe("Atria Dawn");
+  });
+
+  it("pins the single documented preview model", () => {
+    expect(entry.models.map((m) => m.id)).toEqual(["Atria-Dawn-Preview"]);
+  });
+});
+
+describe("provider icons", () => {
+  // This file lives in tests/unit/, so resolve icons against the repo root.
+  const REPO_ROOT = join(dirname(fileURLToPath(import.meta.url)), "..", "..");
+
+  it("ships a /public/providers/{id}.png for every provider in the batch", () => {
+    // getProviderIconSrc() resolves /providers/{id}.png and falls back to the
+    // textIcon tile when the file 404s, so a missing icon is silent in the UI.
+    for (const p of BATCH.map((x) => x.id)) {
+      expect(existsSync(join(REPO_ROOT, "public", "providers", `${p}.png`))).toBe(true);
+    }
+  });
+});
+
+describe("authenticated model discovery", () => {
+  const ROUTE = join(
+    dirname(fileURLToPath(import.meta.url)), "..", "..",
+    "src", "app", "api", "providers", "[id]", "models", "route.js"
+  );
+  const source = readFileSync(ROUTE, "utf8");
+
+  it("registers every batch provider in the /models resolver", () => {
+    // Without an entry here the route answers
+    // 400 "Provider X does not support models listing" and live discovery
+    // silently fails once a key is saved.
+    for (const p of BATCH.map((x) => x.id)) {
+      expect(source).toContain(`${p}: createOpenAIModelsConfig(`);
+    }
+  });
+
+  it("points each entry at that provider's own /models URL", () => {
+    for (const p of BATCH) {
+      const line = source.split("\n").find((l) => l.trim().startsWith(`${p.id}: createOpenAIModelsConfig(`));
+      expect(line, `no models entry for ${p.id}`).toBeTruthy();
+      expect(line).toContain(p.modelsUrl);
+    }
+  });
+});
+
+describe("batch invariants", () => {
+  it("keeps every registry id unique", () => {
+    const ids = REGISTRY.map((e) => e.id);
+    expect(new Set(ids).size).toBe(ids.length);
+  });
+
+  it("does not claim vision for any provider in the batch", () => {
+    // These aggregators relay third-party models; none of them has documented
+    // image input, so no registry entry may assert it.
+    for (const p of BATCH) {
+      const entry = REGISTRY.find((e) => e.id === p.id);
+      expect(entry.serviceKinds ?? ["llm"]).toContain("llm");
+      expect(entry.imageToTextConfig).toBeUndefined();
+    }
+  });
+});