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/国债长期利率平均值.md

@@ -0,0 +1,101 @@
+# 国债长期利率平均值
+
+**文档ID**: 223
+**原始链接**: https://tushare.pro/document/2?doc_id=223
+
+---
+
+## 国债实际长期利率平均值
+
+接口：us_trltr描述：国债实际长期利率平均值限量：单次最大可获取2000行数据，可循环获取权限：用户积累120积分可以使用，积分越高频次越高。具体请参阅积分获取办法
+
+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>date</td>
+<td>str</td>
+<td>N</td>
+<td>日期</td>
+</tr>
+<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>fields</td>
+<td>str</td>
+<td>N</td>
+<td>指定字段</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>date</td>
+<td>str</td>
+<td>Y</td>
+<td>日期</td>
+</tr>
+<tr>
+<td>ltr_avg</td>
+<td>float</td>
+<td>Y</td>
+<td>实际平均利率LT Real Average (10&gt; Yrs)</td>
+</tr>
+</tbody></table>
+接口调用
+
+```
+
+pro = ts.pro_api()
+
+df = pro.us_trltr(start_date='20180101', end_date='20200327')
+
+
+#获取指定字段
+df = pro.us_trltr(start_date='20180101', end_date='20200327', fields='ltr_avg')
+
+```
+
+数据样例
+
+```
+      date ltr_avg
+0     20200327   -0.02
+1     20200326   -0.05
+2     20200325    0.01
+3     20200324   -0.04
+4     20200323    0.04
+...        ...     ...
+1995  20120404    0.57
+1996  20120403    0.58
+1997  20120402    0.53
+1998  20120330    0.57
+1999  20120329    0.51
+```