fix(skills): 禁止自动注入完整技能内容 (#49)

## Summary

- 将 dashscope-image-gen、image-to-image、markdown、tech-diagram、xiaomi-tts
改为仅按需加载，并递增 patch 版本
- 在 Market validator 与 JSON Schema 中禁止 `disable-model-invocation: false`
- 将回归测试接入 `i18n Validate`，同步中英文技能编写规范

## Root cause and impact

这 5 个技能在首次引入时即声明 `disable-model-invocation: false`，导致完整技能正文进入普通请求的
system prompt。修改后市场技能只能声明 `true` 或省略该字段，完整内容仅在显式调用 Skill 工具后加载。

## Validation

- `uv run --quiet scripts/i18n/test_validate_i18n.py`
- `uv run --quiet scripts/i18n/validate-i18n.py`
- `uv run --quiet scripts/i18n/translate.py --check`
- `python3 -m json.tool
scripts/i18n/schema/skill-frontmatter.schema.json`
- `actionlint .github/workflows/i18n-validate.yml`
- `git diff --check`

skills/dashscope-image-gen/SKILL.md

@@ -8,11 +8,11 @@ description: >-
   Use when the user mentions: generate image, draw, text-to-image, create image,
   AI painting, illustration, design picture.
 license: Complete terms in LICENSE.txt
-version: 1.4.1
+version: 1.4.2
 type: procedural
 risk_level: low
 status: enabled
-disable-model-invocation: false
+disable-model-invocation: true
 provider: auto
 tags:
   - media
@@ -25,7 +25,7 @@ requires:
     - Bash
 metadata:
   author: desirecore
-  updated_at: '2026-06-15'
+  updated_at: '2026-07-14'
   i18n:
     default_locale: en-US
     source_locale: zh-CN