test(translator): add data-driven coverage, bug-exposing cases, and real provider smoke

- matrix.js generates N providers x M models from PROVIDER_MODELS
- coverage-all-models + format-roundtrip for structural/semantic checks
- bugs-* files expose known translation issues via it.fails
- real/smoke-providers runs full handleChatCore path against live providers (RUN_REAL=1), concurrent
- registerAll.js eagerly imports translators (Vitest ESM require fix)
- vitest.config: array aliases for subpaths + maxConcurrency 60

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

tests/translator/format-roundtrip.test.js

@@ -0,0 +1,76 @@
+// Tier 2 — Format-pair: for each CLI source format, translate to openai and verify
+// core parts (text, tool, system) survive. Exposes bridge data loss.
+import { describe, it, expect } from "vitest";
+import "./registerAll.js";
+import { translateRequest } from "../../open-sse/translator/index.js";
+import { FORMATS } from "../../open-sse/translator/formats.js";
+
+const T = (src, tgt, body, provider = null) =>
+  translateRequest(src, tgt, "m", body, true, null, provider);
+
+describe("roundtrip: Claude source preserves core fields → OpenAI", () => {
+  const body = {
+    system: "sys",
+    max_tokens: 100,
+    messages: [
+      { role: "user", content: "question" },
+      { role: "assistant", content: [{ type: "tool_use", id: "call_1", name: "search", input: { q: "x" } }] },
+      { role: "user", content: [{ type: "tool_result", tool_use_id: "call_1", content: "result" }] },
+    ],
+  };
+  const out = T(FORMATS.CLAUDE, FORMATS.OPENAI, body);
+
+  it("system → system role", () => {
+    expect(out.messages.some((m) => m.role === "system" && m.content === "sys")).toBe(true);
+  });
+  it("tool_use → assistant.tool_calls with matching id", () => {
+    const asst = out.messages.find((m) => m.tool_calls);
+    expect(asst?.tool_calls?.[0]?.id).toBe("call_1");
+  });
+  it("tool_result → tool message with matching id", () => {
+    const tool = out.messages.find((m) => m.role === "tool");
+    expect(tool?.tool_call_id).toBe("call_1");
+    expect(tool?.content).toContain("result");
+  });
+  it("tool arguments are valid JSON string", () => {
+    const asst = out.messages.find((m) => m.tool_calls);
+    expect(() => JSON.parse(asst.tool_calls[0].function.arguments)).not.toThrow();
+  });
+});
+
+describe("roundtrip: OpenAI tools → Claude → keeps tool name", () => {
+  const out = T(FORMATS.OPENAI, FORMATS.CLAUDE, {
+    messages: [{ role: "user", content: "hi" }],
+    tools: [{ type: "function", function: { name: "my_tool", description: "d", parameters: { type: "object", properties: {} } } }],
+  }, "anthropic-compatible-x");
+
+  it("tool name survives openai→claude", () => {
+    expect(JSON.stringify(out)).toContain("my_tool");
+  });
+});
+
+describe("roundtrip: parallel tool calls keep distinct ids", () => {
+  // Claude assistant with 2 parallel tool_use → openai must keep 2 distinct ids
+  const out = T(FORMATS.CLAUDE, FORMATS.OPENAI, {
+    messages: [
+      { role: "assistant", content: [
+        { type: "tool_use", id: "call_a", name: "f1", input: {} },
+        { type: "tool_use", id: "call_b", name: "f2", input: {} },
+      ] },
+      { role: "user", content: [
+        { type: "tool_result", tool_use_id: "call_a", content: "ra" },
+        { type: "tool_result", tool_use_id: "call_b", content: "rb" },
+      ] },
+    ],
+  });
+
+  it("two tool_calls, two distinct ids", () => {
+    const asst = out.messages.find((m) => m.tool_calls);
+    const ids = asst.tool_calls.map((tc) => tc.id);
+    expect(new Set(ids).size).toBe(2);
+  });
+  it("each tool_call has a matching tool result", () => {
+    const toolMsgs = out.messages.filter((m) => m.role === "tool");
+    expect(toolMsgs.length).toBe(2);
+  });
+});