feat(core): implement agent skill

[fang-tech]

close #92

[codecov]

Codecov Report

❌ Patch coverage is 82.42991% with 94 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
...c/main/java/io/agentscope/core/skill/SkillBox.java	72.41%	37 Missing and 11 partials ⚠️
...re/skill/repository/FileSystemSkillRepository.java	84.07%	22 Missing and 3 partials ⚠️
...e/src/main/java/io/agentscope/core/ReActAgent.java	0.00%	7 Missing and 1 partial ⚠️
...gentscope/core/skill/util/MarkdownSkillParser.java	92.59%	2 Missing and 2 partials ⚠️
.../main/java/io/agentscope/core/skill/SkillHook.java	88.00%	1 Missing and 2 partials ⚠️
.../java/io/agentscope/core/skill/util/SkillUtil.java	80.00%	0 Missing and 3 partials ⚠️
...ore/skill/repository/AgentSkillRepositoryInfo.java	80.00%	2 Missing ⚠️
...pe/core/skill/repository/AgentSkillRepository.java	0.00%	1 Missing ⚠️

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[Copilot]

Pull request overview

This PR implements the agent skill feature as proposed by Anthropic, allowing agents to dynamically load specialized capabilities from skill directories. The implementation adds support for registering, managing, and using agent skills within the AgentScope framework.

• Adds comprehensive bilingual documentation (English and Chinese) explaining agent skill concepts, APIs, and usage examples
• Implements core agent skill functionality including YAML frontmatter parsing, skill registration, and integration with ReActAgent
• Provides complete test coverage for all new components including YamlFrontmatter parser, Toolkit agent skill APIs, and ToolRegistry operations

Reviewed changes

Copilot reviewed 12 out of 12 changed files in this pull request and generated 11 comments.

Show a summary per file

File	Description
docs/en/task/agent-skill.md	English documentation for agent skills with comprehensive examples and best practices
docs/zh/task/agent-skill.md	Chinese translation of agent skill documentation
agentscope-core/src/main/java/io/agentscope/core/util/YamlFrontmatter.java	New utility class for parsing YAML frontmatter from markdown files
agentscope-core/src/main/java/io/agentscope/core/tool/Toolkit.java	Extended with agent skill registration, retrieval, and removal methods
agentscope-core/src/main/java/io/agentscope/core/tool/ToolkitConfig.java	Added configuration for agent skill instruction and template formatting
agentscope-core/src/main/java/io/agentscope/core/tool/ToolRegistry.java	Added concurrent map storage and operations for agent skills
agentscope-core/src/main/java/io/agentscope/core/ReActAgent.java	Modified getSysPrompt() to append agent skill prompts automatically
agentscope-core/src/test/java/io/agentscope/core/util/YamlFrontmatterTest.java	Comprehensive test suite covering normal cases, edge cases, and error scenarios
agentscope-core/src/test/java/io/agentscope/core/tool/ToolkitTest.java	Tests for agent skill registration, validation, and removal
agentscope-core/src/test/java/io/agentscope/core/tool/ToolRegistryTest.java	Tests for registry operations including concurrent access
agentscope-core/src/test/java/io/agentscope/core/agent/test/TestConstants.java	Added default agent skill instruction and template constants
agentscope-core/src/test/java/io/agentscope/core/agent/ReActAgentTest.java	Integration test verifying agent skill prompt appending

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Pull request overview

Copilot reviewed 12 out of 12 changed files in this pull request and generated 9 comments.

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Pull request overview

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All committers have signed the CLA.

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Pull request overview

Copilot reviewed 14 out of 14 changed files in this pull request and generated 4 comments.

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Pull request overview

Copilot reviewed 33 out of 33 changed files in this pull request and generated no new comments.

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[AlbumenJ]

1. ReActAgent does not need to hold skillBox.
2. Extract skillHook into a separate class.

Others LGTM