spec-buildlisted

# spec-build Drives spec-driven, per-task delivery. This is step 3 of the workflow: `spec-ideate` → `spec-tasks` → `spec-build`. ## When to use **Only** when a `specs/NNN_feature_slug/tasks/` directory already exists (produced by `spec-tasks`) and the user is working through that task list — delivering the tasks one at a time so each can be verified independently. For any other code change — ad-hoc fixes, upgrades, one-off implementation not tied to a spec — use the `build` skill instead. ## Follow the `build` skill For all repo commands (test / lint / format / build / run) and coding conventions, use the **`build`** skill — this skill does not restate them. `build` is the general reference; `spec-build` only adds the per-task delivery loop below. ## Per-task delivery loop Deliver **one task at a time** and let the user verify each independently: 1. Pick the next unchecked task from `specs/NNN_feature_slug/tasks/README.md`. 2. Work directly on `main` — no feature branch (solo portfolio repo). 3. Implement **only that task's scope**, following the `build` skill's commands and conventions. 4. Run the task's QA (tests / lint / format / typecheck for the languages touched — see the `build` skill). 5. Tick the task off in `tasks/README.md` and set its `Status: Done`. 6. **Stop and hand back with the changes left unstaged.** Do not commit or push. The user reviews the diff, then commits/pushes and verifies independently. Only continue to the next task on the user's expli