Code scanning alerts link to GitHub Issues to facilitate collaboration and work management [GA]

### Value Prop

Security teams and developers can link code scanning alerts directly to GitHub Issues, bringing security remediation into the same collaboration and planning workflows they already use for feature work. Instead of tracking vulnerabilities in spreadsheets or jumping between security tools, teams get native traceability from alert to issue to pull request within GitHub. With GA, this extends to full programmatic access via REST APIs and webhooks, enabling automated triage workflows and integration with existing processes at scale.

### Expected Outcome

Shorter time-to-remediation for security findings by removing friction between detection and developer action. Security teams can create actionable issues from alerts, assign them to the right developers, and track progress through existing project boards. Developers see linked security alerts directly on their issues, so they understand the "why" behind the work without switching tools. At GA, API and webhook support lets enterprises build automated pipelines reducing manual triage overhead and ensuring no critical finding falls through the cracks.

此路线图 issue 未指定任何仓库文件、测试或实现入口。首先明确将 code scanning 警报与 GitHub Issues 关联的范围，包括 REST API 和 webhook 的要求；应根据已约定的 GA 行为和集成覆盖范围定义 done。

由索引模型根据 Issue 内容生成。