Commit at every TDD phase transition

Each accepted phase transition is a checkpoint. Commit at:

• spike: exploratory work before writing a failing test. Commit message: tdd(<goalId>:spike): <imperative summary of exploration>
• red→green: test passes after the production fix. Commit message: tdd(<goalId>:green): <imperative summary>
• green→refactor: cleanup done, all tests still pass. Commit message: tdd(<goalId>:refactor): <what changed>
• discard (red): goal or behavior abandoned with uncommitted production code in the working tree. Commit message: tdd(<goalId>:red): discard — <reason>

<goalId> is the bare numeric DB id returned by tdd_goal (action: create) (e.g., 7).

Examples:

tdd(7:spike): explore lifecycle.ts shape before writing test
tdd(7:green): implement sum() to pass failing assertion
tdd(7:refactor): extract add-three helper
tdd(8:green): handle negative inputs in sum()
tdd(8:red): discard — step too large, re-decomposing

Rules

1. Never commit during red itself — by definition the suite is failing. The red state is for discard only: commit after abandoning the goal or behavior with uncommitted production code still in the tree.
2. If no refactor is needed after green, skip the refactor commit and move on.
3. The post-commit hook captures the commit hash and writes a commits row to the DB. It records changed files against the most-recent test run — no message-tag parsing.

Squash after the goal is complete

After the main agent runs the seven-step audit, squash all tdd(<goalId>:*) commits for the goal into a single conventional commit whose type (fix, feat, refactor, test) reflects what the goal actually delivered:

fix(playground): sum handles negative inputs and off-by-one

Signed-off-by: ...