pb-build

Execute the spec task-by-task. The spec is the source of truth.

Workflow

1. Load spec and resolve tasks

• Resolve <spec-dir> from actual directory names under specs/. Never guess.
• Parse ### Task X.Y: blocks (4 fields, schema in docs/contract.md), build the dependency graph from DependsOn (cycle → stop), and execute in dependency order. Independent tasks may run in parallel subagents; same-file tasks must not.

2. Per task — strict TDD loop

1. Red: write the failing test first (unit + property tests where applicable; for bug fixes the reproducer IS the red test) → verify it fails. If you wrote code before the test, delete it and start over.
2. Green: minimum implementation → verify pass.
3. Refactor: clean up → suite still green.
4. Verify layers: per the project testing principle, add integration/E2E/fuzz coverage the task's test matrix calls for — boundary and exception paths included. No production code without a failing test first; no completion claims without fresh evidence (run the command, paste output, check exit code — "should pass" is a lie).

3. Mutation testing — selective and scope-bounded