fix(skills): 添加脚本路径强制规则，修复 docx/pptx/xlsx 脚本找不到的问题

Agent 执行技能内置脚本时 cwd 不在技能目录，导致 python scripts/... 相对路径失败。
在 L2 规范中增加 Script Path Rule，要求使用 <skill-dir> 拼接完整路径。

skills/pptx/SKILL.md

@@ -38,7 +38,7 @@ metadata:
       description: >-
         Use this skill any time a .pptx file is involved in any way — as input, output, or both. This includes: creating slide decks, pitch decks, or presentations; reading, parsing, or extracting text from any .pptx file (even if the extracted content will be used elsewhere, like in an email or summary); editing, modifying, or updating existing presentations; combining or splitting slide files; working with templates, layouts, speaker notes, or comments. Trigger whenever the user mentions "deck," "slides," "presentation," or references a .pptx filename, regardless of what they plan to do with the content afterward. If a .pptx file needs to be opened, created, or touched, use this skill. Use when 用户提到 PPT、演示文稿、幻灯片、演讲稿、汇报材料、 pptx、创建演示、编辑幻灯片。
       body: ./SKILL.zh-CN.md
-      source_hash: sha256:761da55f1e450adc
+      source_hash: sha256:a952bf5622ede8e0
       translated_by: human
     en-US:
       name: Presentation Processing
@@ -46,8 +46,8 @@ metadata:
       description: >-
         Use this skill any time a .pptx file is involved in any way — as input, output, or both. This includes: creating slide decks, pitch decks, or presentations; reading, parsing, or extracting text from any .pptx file (even if the extracted content will be used elsewhere, like in an email or summary); editing, modifying, or updating existing presentations; combining or splitting slide files; working with templates, layouts, speaker notes, or comments. Trigger whenever the user mentions "deck," "slides," "presentation," or references a .pptx filename, regardless of what they plan to do with the content afterward. If a .pptx file needs to be opened, created, or touched, use this skill. Use when the user mentions PPT, presentation, slides, speaker notes, briefing materials, pptx, creating presentations, or editing slides.
       body: ./SKILL.md
-      source_hash: sha256:761da55f1e450adc
-      translated_by: ai:claude-opus-4-7
+      source_hash: sha256:a952bf5622ede8e0
+      translated_by: human
       translated_at: '2026-05-03'
 market:
   icon: >-
@@ -91,6 +91,19 @@ pptx is a **Procedural Skill** providing full PowerPoint presentation processing
 
 ## L2: Detailed Specification
 
+### Script Path Rule (mandatory)
+
+The Python scripts bundled with this skill live inside the skill installation directory. You **MUST use full paths** when invoking them — never use bare relative paths.
+
+The skill directory is provided by the `<skill-dir>` tag in the context. Prefix all `scripts/` commands accordingly:
+
+```bash
+python "<skill-dir>/scripts/office/unpack.py" presentation.pptx unpacked/
+python "<skill-dir>/scripts/office/pack.py" unpacked/ output.pptx
+```
+
+**NEVER** run `python scripts/office/unpack.py` directly — that relative path does not exist in the user's working directory.
+
 ## Prerequisites
 
 ### Python 3 (required — needed when reading and editing existing PPTX)

skills/pptx/SKILL.zh-CN.md

@@ -21,6 +21,19 @@ pptx 是一个**流程型技能（Procedural Skill）**，提供 PowerPoint 演
 
 ## L2：详细规范
 
+### 脚本路径规则（强制）
+
+本技能自带的 Python 脚本位于技能安装目录内。执行时**必须使用完整路径**，不能使用相对路径。
+
+技能目录由上下文中的 `<skill-dir>` 标签提供。所有 `scripts/` 开头的命令都应拼接为：
+
+```bash
+python "<skill-dir>/scripts/office/unpack.py" presentation.pptx unpacked/
+python "<skill-dir>/scripts/office/pack.py" unpacked/ output.pptx
+```
+
+**禁止**直接执行 `python scripts/office/unpack.py`——该相对路径在用户工作目录下不存在。
+
 ## Prerequisites
 
 ### Python 3（必需 — 读取和编辑现有 PPTX 时需要）