sds-coder (The Implementation Skill)

sds-coder is the workhorse of the SDS lifecycle. It coordinates and supervises code generation, ensuring that all implementation steps are strictly bound to accepted specifications.

[!NOTE] Ecosystem Status: 🔵 Planned / 模块开发状态：规划中 This module (sds-coder) is currently Planned as outlined in our Roadmap. The specifications and instructions below describe the target design and behavioral interface, but the physical skill package is not yet active. 本模块目前处于规划中阶段。下述规范和指令描述了其目标架构和行为定义，但其实体技能包尚未正式激活。

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Key Capabilities

1. Subagent-Driven Development (SDD): For complex changesets, the coder skill spawns dedicated, focused subagents to handle isolated files or modules. This maintains tight context boundaries and improves code quality.
2. Automatic Trace Annotation: Automatically injects @sds-trace: <capability_id>:AC-n tag comments at the entry and exit points of implementation methods and test suites.
3. Defense-in-Depth Test Generation: Derives automated unit and integration tests directly from the spec's ACs rather than reverse-engineering the written code.
4. Single-Writer Enforcement: Verifies that business domains have strict boundary isolation and that no file writes violate local module constraints.