Ln 402 Task Reviewer

This is a mandatory quality gate that runs after every task execution in the LN-402 workflow. It loads the task and parent story independently, validates against acceptance criteria, checks for code quality issues like dead code and config hygiene, verifies test coverage with risk-based limits, and either marks the task Done or sends it back To Rework with specific fix guidance. The workflow includes a spec-first gate that does a quick AC scan before diving into full quality checks, plus side-effect bug detection that creates separate bug tasks for issues found outside the original scope. It supports plan mode for review planning and integrates with hex-graph MCP tools for semantic diff analysis when available. Not optional, runs on every single task, no batching or skipping allowed.