[FEL] MCP streamable HTTP server implemented with MCP SDK

[relat-ivity]

🔗 相关问题 / Related Issue

Issue 链接 / Issue Link: #342 👈👈

• 我已经创建了相关 Issue 并进行了讨论 / I have created and discussed the related issue
• 这是一个微小的修改（如错别字），不需要 Issue / This is a trivial change (like typo fix) that doesn't need an issue

📋 变更类型 / Type of Change

• 🐛 Bug 修复 / Bug fix (non-breaking change which fixes an issue)
• ✨ 新功能 / New feature (non-breaking change which adds functionality)
• 💥 破坏性变更 / Breaking change (fix or feature that would cause existing functionality to not work as expected)
• 📚 文档更新 / Documentation update
• 🔧 重构 / Refactoring (no functional changes)
• ⚡ 性能优化 / Performance improvement
• 📦 依赖升级 / Dependency upgrade (update dependencies to newer versions)
• 🚀 功能增强 / Feature enhancement (improve existing functionality without breaking changes)
• 🧹 代码清理 / Code cleanup

📝 变更目的 / Purpose of the Change

根据MCP协议2025-06-18版本新的规范，MCP传输调整为streamable HTTP。并且新增服务器Elicitation与服务器Log通知等新功能。

在原有的FEL中实现的SSE MCP服务器中接入这些新功能需要较大工作量，所以需要接入MCP SDK实现。

📋 主要变更 / Brief Changelog

• 在FEL的tool-mcp-server插件中添加0.14.0版本的MCP Java SDK的依赖
• 新建DefaultStreamableSyncMcpServer类使用MCP SDK构建同步Streamable MCP服务器
• 新建DefaultMcpStreamableServerTransportProvider类使用FIT的HTTP实现完成Streamable MCP服务器的HTTP传输逻辑

🧪 验证变更 / Verifying this Change

测试步骤 / Test Steps

1. 使用npx @modelcontextprotocol/inspector测试服务器功能
2. 使用Postman测试Inpector测不到的API，例如GET建立SSE

测试覆盖 / Test Coverage

• 我已经添加了单元测试 / I have added unit tests
• 所有现有测试都通过 / All existing tests pass
• 我已经进行了手动测试 / I have performed manual testing

📸 截图 / Screenshots

✅ 贡献者检查清单 / Contributor Checklist

请确保你的 Pull Request 符合以下要求 / Please ensure your Pull Request meets the following requirements:

基本要求 / Basic Requirements:

• 确保有 GitHub Issue 对应这个变更（微小变更如错别字除外）/ Make sure there is a Github issue filed for the change (trivial changes like typos excluded)
• 你的 Pull Request 只解决一个 Issue，没有包含其他不相关的变更 / Your PR addresses just this issue, without pulling in other changes - one PR resolves one issue
• PR 中的每个 commit 都有有意义的主题行和描述 / Each commit in the PR has a meaningful subject line and body

代码质量 / Code Quality:

• 我的代码遵循项目的代码规范 / My code follows the project's coding standards
• 我已经进行了自我代码审查 / I have performed a self-review of my code
• 我已经为复杂的代码添加了必要的注释 / I have commented my code, particularly in hard-to-understand areas

测试要求 / Testing Requirements:

• 我已经编写了必要的单元测试来验证逻辑正确性 / I have written necessary unit-tests to verify the logic correction
• 当存在跨模块依赖时，我尽量使用了 mock / I have used mocks when cross-module dependencies exist
• 基础检查通过：mvn -B clean package -Dmaven.test.skip=true，elsa README 中的编译检查 / Basic checks pass
• 单元测试通过：mvn clean install / Unit tests pass

文档和兼容性 / Documentation and Compatibility:

• 我已经更新了相应的文档 / I have made corresponding changes to the documentation
• 如果有破坏性变更，我已经在 PR 描述中详细说明 / If there are breaking changes, I have documented them in detail
• 我已经考虑了向后兼容性 / I have considered backward compatibility

📋 附加信息 / Additional Notes

由于引入MCP Java SDK中使用SLF4J作为日志，启动时会warning:

SLF4J(W): No SLF4J providers were found.
SLF4J(W): Defaulting to no-operation (NOP) logger implementation
SLF4J(W): See https://www.slf4j.org/codes.html#noProviders for further details.

将在后续Issue中改进

审查者注意事项 / Reviewer Notes: