fix(packages): resolve npm bin entrypoint detection (#567)

Fix npm/global bin entrypoint detection for CLI and MCP server by normalizing real entry paths, including symlinked invocations.

packages/cli/tests/bin.test.ts

@@ -0,0 +1,52 @@
+import assert from "node:assert/strict";
+import { mkdtemp, rm, symlink } from "node:fs/promises";
+import { tmpdir } from "node:os";
+import { join } from "node:path";
+import { fileURLToPath } from "node:url";
+import { spawnSync } from "node:child_process";
+import test from "node:test";
+
+const packageDir = fileURLToPath(new URL("..", import.meta.url));
+const cliSource = fileURLToPath(new URL("../src/cli.ts", import.meta.url));
+
+test("prints version when invoked through an npm-style symlink", async () => {
+  const bin = await symlinkedCli();
+  try {
+    const result = runDbx(bin, ["--version"]);
+
+    assert.equal(result.status, 0);
+    assert.match(result.stdout, /^\d+\.\d+\.\d+\n$/);
+    assert.equal(result.stderr, "");
+  } finally {
+    await rm(bin.dir, { recursive: true, force: true });
+  }
+});
+
+test("prints capabilities when invoked through an npm-style symlink", async () => {
+  const bin = await symlinkedCli();
+  try {
+    const result = runDbx(bin, ["capabilities", "--json"]);
+
+    assert.equal(result.status, 0);
+    assert.equal(result.stderr, "");
+    const payload = JSON.parse(result.stdout) as { directQueryTypes: string[]; bridgeRequiredTypes: string[] };
+    assert.ok(payload.directQueryTypes.includes("postgres"));
+    assert.ok(payload.bridgeRequiredTypes.includes("oracle"));
+  } finally {
+    await rm(bin.dir, { recursive: true, force: true });
+  }
+});
+
+async function symlinkedCli() {
+  const dir = await mkdtemp(join(tmpdir(), "dbx-cli-bin-"));
+  const path = join(dir, "dbx");
+  await symlink(cliSource, path);
+  return { dir, path };
+}
+
+function runDbx(bin: { path: string }, args: string[]) {
+  return spawnSync(process.execPath, ["--import", "tsx", bin.path, ...args], {
+    cwd: packageDir,
+    encoding: "utf-8",
+  });
+}