Add bd exec bridge and mutation API routes with tests

tests/api/mutations-routes.test.ts

@@ -0,0 +1,55 @@
+import test from 'node:test';
+import assert from 'node:assert/strict';
+
+import { POST as createPost } from '../../src/app/api/beads/create/route';
+import { POST as reopenPost } from '../../src/app/api/beads/reopen/route';
+import { POST as commentPost } from '../../src/app/api/beads/comment/route';
+
+async function readJson(response: Response): Promise<any> {
+  const text = await response.text();
+  return text ? JSON.parse(text) : {};
+}
+
+test('create route returns 400 for invalid payload', async () => {
+  const response = await createPost(
+    new Request('http://localhost/api/beads/create', {
+      method: 'POST',
+      body: JSON.stringify({ projectRoot: '', title: '' }),
+      headers: { 'content-type': 'application/json' },
+    }),
+  );
+
+  assert.equal(response.status, 400);
+  const data = await readJson(response);
+  assert.equal(data.ok, false);
+  assert.equal(data.error.classification, 'bad_args');
+});
+
+test('reopen route returns 400 for missing id', async () => {
+  const response = await reopenPost(
+    new Request('http://localhost/api/beads/reopen', {
+      method: 'POST',
+      body: JSON.stringify({ projectRoot: 'C:/repo' }),
+      headers: { 'content-type': 'application/json' },
+    }),
+  );
+
+  assert.equal(response.status, 400);
+  const data = await readJson(response);
+  assert.equal(data.ok, false);
+});
+
+test('comment route returns 400 for missing comment text', async () => {
+  const response = await commentPost(
+    new Request('http://localhost/api/beads/comment', {
+      method: 'POST',
+      body: JSON.stringify({ projectRoot: 'C:/repo', id: 'bb-1' }),
+      headers: { 'content-type': 'application/json' },
+    }),
+  );
+
+  assert.equal(response.status, 400);
+  const data = await readJson(response);
+  assert.equal(data.ok, false);
+  assert.equal(typeof data.error.message, 'string');
+});