Solution Design
Covers Stage 3, SOLUTION_DISCOVERY (docs/PROCESS_CONTRACT.md §5). An AI
execution provider may research alternatives and build disposable
prototypes, with write access limited to a sandbox branch — it may never
merge to a protected branch from this stage, and it never decides the
recommended direction on its own.
Rejection path
Problem mis-scoped → back to problem-definition at PROBLEM_DISCOVERY
(docs/PROCESS_CONTRACT.md, stage SOLUTION_DISCOVERY).