feat(ai): add Alibaba DashScope recipe (#59 split, part 1/2)

12th recipe. text-embedding-v3 (current) + text-embedding-v2; 1024
default dims with Matryoshka options [64, 128, 256, 512, 768, 1024].

OpenAI-compatible at dashscope-intl.aliyuncs.com. China-region users
override via cfg.base_urls['dashscope']; v0.32 ships with the
international default.

Conservative max_batch_tokens=8192 + chars_per_token=2 declared because
Alibaba doesn't publish a hard batch limit and text-embedding-v3 mixes
English + CJK heavily (CJK density closer to Voyage than OpenAI tiktoken).

Tests: bun test test/ai/ — 106/106 (5 new + 101 prior).

Plan: ~/.claude/plans/ok-lets-turn-this-enumerated-sonnet.md (commit 6
of 11). Reworked from #59 (DashScope+Zhipu split into 2 commits per
the plan; Zhipu lands next).

Co-Authored-By: Magicray1217 <267836857+Magicray1217@users.noreply.github.com>
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

test/ai/recipe-dashscope.test.ts

@@ -0,0 +1,57 @@
+/**
+ * DashScope (Alibaba) recipe smoke (Commit 6 of the v0.32 wave).
+ */
+
+import { describe, expect, test } from 'bun:test';
+import { getRecipe } from '../../src/core/ai/recipes/index.ts';
+import { defaultResolveAuth } from '../../src/core/ai/gateway.ts';
+import { AIConfigError } from '../../src/core/ai/errors.ts';
+
+describe('recipe: dashscope', () => {
+  test('registered with expected shape', () => {
+    const r = getRecipe('dashscope');
+    expect(r).toBeDefined();
+    expect(r!.id).toBe('dashscope');
+    expect(r!.tier).toBe('openai-compat');
+    expect(r!.implementation).toBe('openai-compatible');
+    expect(r!.base_url_default).toBe(
+      'https://dashscope-intl.aliyuncs.com/compatible-mode/v1',
+    );
+    expect(r!.auth_env?.required).toEqual(['DASHSCOPE_API_KEY']);
+  });
+
+  test('embedding touchpoint declares text-embedding-v3 first + 1024 dims', () => {
+    const r = getRecipe('dashscope')!;
+    expect(r.touchpoints.embedding).toBeDefined();
+    expect(r.touchpoints.embedding!.models[0]).toBe('text-embedding-v3');
+    expect(r.touchpoints.embedding!.models).toContain('text-embedding-v2');
+    expect(r.touchpoints.embedding!.default_dims).toBe(1024);
+    expect(r.touchpoints.embedding!.dims_options).toEqual([64, 128, 256, 512, 768, 1024]);
+    // Matryoshka: every dims option ≤ 2000 (HNSW-compatible).
+    for (const d of r.touchpoints.embedding!.dims_options ?? []) {
+      expect(d).toBeLessThanOrEqual(2000);
+    }
+  });
+
+  test('default auth: DASHSCOPE_API_KEY set → "Bearer <key>"', () => {
+    const r = getRecipe('dashscope')!;
+    const auth = defaultResolveAuth(
+      r,
+      { DASHSCOPE_API_KEY: 'sk-dashscope-fake' },
+      'embedding',
+    );
+    expect(auth.headerName).toBe('Authorization');
+    expect(auth.token).toBe('Bearer sk-dashscope-fake');
+  });
+
+  test('default auth: missing DASHSCOPE_API_KEY → AIConfigError', () => {
+    const r = getRecipe('dashscope')!;
+    expect(() => defaultResolveAuth(r, {}, 'embedding')).toThrow(AIConfigError);
+  });
+
+  test('declares chars_per_token + max_batch_tokens for safer batching', () => {
+    const r = getRecipe('dashscope')!;
+    expect(r.touchpoints.embedding!.max_batch_tokens).toBeGreaterThan(0);
+    expect(r.touchpoints.embedding!.chars_per_token).toBeGreaterThan(0);
+  });
+});