feat: multimodal image clients, workspaces, Tushare skill, test fixes

- Replace monolithic image_message_client with HTTP/OCR/legacy modules; tighten OpenAI transport + tool schemas for multimodal downgrade to OCR specialist path.
- Add image/stock workspace prompts (META/SOUL/ROLE_SYSTEM); register experts; tweak specialist agent/direct loop/query_image_attachment.
- Add bundled runtime/skills/tushare-finance (references, api_client, SKILL metadata).
- Document OCR-related env vars; admin chat tweaks; README; weixin_install Ensure-OfficialPluginRuntimeDeps helper.
- Tests: multimodal downgrade + OCR coverage, strict tool pairing in attachment replay guard, workspace contract skips _internal/_system dirs, router/trace/prompt guards.

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

runtime/skills/tushare-finance/reference/接口文档/港股交易日历.md

@@ -0,0 +1,95 @@
+# 港股交易日历
+
+**文档ID**: 250
+**原始链接**: https://tushare.pro/document/2?doc_id=250
+
+---
+
+## 港股交易日历
+
+接口：hk_tradecal描述：获取交易日历限量：单次最大2000权限：用户积累2000积分才可调取
+
+输入参数
+
+<table>
+<thead>
+<tr>
+<th>名称</th>
+<th>类型</th>
+<th>必选</th>
+<th>描述</th>
+</tr>
+</thead>
+<tbody><tr>
+<td>start_date</td>
+<td>str</td>
+<td>N</td>
+<td>开始日期</td>
+</tr>
+<tr>
+<td>end_date</td>
+<td>str</td>
+<td>N</td>
+<td>结束日期</td>
+</tr>
+<tr>
+<td>is_open</td>
+<td>str</td>
+<td>N</td>
+<td>是否交易 '0'休市 '1'交易</td>
+</tr>
+</tbody></table>
+输出参数
+
+<table>
+<thead>
+<tr>
+<th>名称</th>
+<th>类型</th>
+<th>默认显示</th>
+<th>描述</th>
+</tr>
+</thead>
+<tbody><tr>
+<td>cal_date</td>
+<td>str</td>
+<td>Y</td>
+<td>日历日期</td>
+</tr>
+<tr>
+<td>is_open</td>
+<td>int</td>
+<td>Y</td>
+<td>是否交易 '0'休市 '1'交易</td>
+</tr>
+<tr>
+<td>pretrade_date</td>
+<td>str</td>
+<td>Y</td>
+<td>上一个交易日</td>
+</tr>
+</tbody></table>
+接口示例
+
+```
+
+pro = ts.pro_api()
+
+df = pro.hk_tradecal(start_date='20200101', end_date='20200708')
+
+
+```
+
+数据示例
+
+```
+     cal_date     is_open pretrade_date
+    0  20200708        1      20200707
+    1  20200707        1      20200706
+    2  20200706        1      20200703
+    3  20200705        0      20200702
+    4  20200704        0      20200702
+    5  20200703        1      20200702
+    6  20200702        1      20200630
+    7  20200701        0      20200629
+```