Implement from Spec (with GitHub Spec Kit)

Step 6 of 6 in the Reverse Engineering to Spec-Driven Development process.

Directory Convention

All artifact paths use a single convention:

• specs/ -- canonical location for all specifications and implementation plans
• docs/gap-analysis-report.md -- phased implementation roadmap
• .stackshift-state.json -- session state and progress tracking

Context Routing

Determine execution context before proceeding.

Run git branch --show-current to get the current branch name.