Feat/claude skills management (#237)

* feat(skills): add Claude Skills management feature

Implement complete Skills management system with repository discovery,
installation, and lifecycle management capabilities.

Backend:
- Add SkillService with GitHub integration and installation logic
- Implement skill commands (list, install, uninstall, check updates)
- Support multiple skill repositories with caching

Frontend:
- Add Skills management page with repository browser
- Create SkillCard and RepoManager components
- Add badge, card, table UI components
- Integrate Skills API with Tauri commands

Files: 10 files changed, 1488 insertions(+)

* feat(skills): integrate Skills feature into application

Integrate Skills management feature with complete dependency updates,
configuration structure extensions, and internationalization support.

Dependencies:
- Add @radix-ui/react-visually-hidden for accessibility
- Add anyhow, zip, serde_yaml, tempfile for Skills backend
- Enable chrono serde feature for timestamp serialization

Backend Integration:
- Extend MultiAppConfig with SkillStore field
- Implement skills.json migration from legacy location
- Register SkillService and skill commands in main app
- Export skill module in commands and services

Frontend Integration:
- Add Skills page route and dialog in App
- Integrate Skills UI with main navigation

Internationalization:
- Add complete Chinese translations for Skills UI
- Add complete English translations for Skills UI

Code Quality:
- Remove redundant blank lines in gemini_mcp.rs
- Format log statements in mcp.rs

Tests:
- Update import_export_sync tests for SkillStore
- Update mcp_commands tests for new structure

Files: 16 files changed, 540 insertions(+), 39 deletions(-)

* style(skills): improve SkillsPage typography and spacing

Optimize visual hierarchy and readability of Skills page:
- Reduce title size from 2xl to lg with tighter tracking
- Improve description spacing and color contrast
- Enhance empty state with better text hierarchy
- Use explicit gray colors for better dark mode support

* feat(skills): support custom subdirectory path for skill scanning

Add optional skillsPath field to SkillRepo to enable scanning skills
from subdirectories (e.g., "skills/") instead of repository root.

Changes:
- Backend: Add skillsPath field with subdirectory scanning logic
- Frontend: Add skillsPath input field and display in repo list
- Presets: Add cexll/myclaude repo with skills/ subdirectory
- Code quality: Fix clippy warnings (dedup logic, string formatting)

Backward compatible: skillsPath is optional, defaults to root scanning.

* refactor(skills): improve repo manager dialog layout

Optimize dialog structure with fixed header and scrollable content:
- Add flexbox layout with fixed header and scrollable body
- Remove outer border wrapper for cleaner appearance
- Match SkillsPage design pattern for consistency
- Improve UX with better content hierarchy

src-tauri/src/app_config.rs

@@ -2,6 +2,8 @@ use serde::{Deserialize, Serialize};
 use std::collections::HashMap;
 use std::str::FromStr;
 
+use crate::services::skill::SkillStore;
+
 /// MCP 服务器应用状态（标记应用到哪些客户端）
 #[derive(Debug, Clone, Serialize, Deserialize, Default, PartialEq)]
 pub struct McpApps {
@@ -221,6 +223,9 @@ pub struct MultiAppConfig {
     /// Prompt 配置（按客户端分治）
     #[serde(default)]
     pub prompts: PromptRoot,
+    /// Claude Skills 配置
+    #[serde(default)]
+    pub skills: SkillStore,
     /// 通用配置片段（按应用分治）
     #[serde(default)]
     pub common_config_snippets: CommonConfigSnippets,
@@ -245,6 +250,7 @@ impl Default for MultiAppConfig {
             apps,
             mcp: McpRoot::default(),
             prompts: PromptRoot::default(),
+            skills: SkillStore::default(),
             common_config_snippets: CommonConfigSnippets::default(),
             claude_common_config_snippet: None,
         }
@@ -288,11 +294,36 @@ impl MultiAppConfig {
             ));
         }
 
+        let has_skills_in_config = value
+            .as_object()
+            .is_some_and(|map| map.contains_key("skills"));
+
         // 解析 v2 结构
         let mut config: Self =
             serde_json::from_value(value).map_err(|e| AppError::json(&config_path, e))?;
         let mut updated = false;
 
+        if !has_skills_in_config {
+            let skills_path = get_app_config_dir().join("skills.json");
+            if skills_path.exists() {
+                match std::fs::read_to_string(&skills_path) {
+                    Ok(content) => match serde_json::from_str::<SkillStore>(&content) {
+                        Ok(store) => {
+                            config.skills = store;
+                            updated = true;
+                            log::info!("已从旧版 skills.json 导入 Claude Skills 配置");
+                        }
+                        Err(e) => {
+                            log::warn!("解析旧版 skills.json 失败: {e}");
+                        }
+                    },
+                    Err(e) => {
+                        log::warn!("读取旧版 skills.json 失败: {e}");
+                    }
+                }
+            }
+        }
+
         // 确保 gemini 应用存在（兼容旧配置文件）
         if !config.apps.contains_key("gemini") {
             config