dev-feature-planlisted

# Dev Feature Plan Translates a completed, analyzed feature spec into an implementation plan and task list. Requires no client input after handoff. ## Inputs - **Spec**: `.specify/features/{slug}/spec.md` (required) - **Dev findings**: `.specify/features/{slug}/dev-findings.md` (optional, from pm-epic-writing) ## Step 1 — Validate the branch ```bash git rev-parse --abbrev-ref HEAD ``` A feature branch matches `^[0-9]{3,}-` (sequential, `001-feature-name`) or `^[0-9]{8}-[0-9]{6}-` (timestamp). On a feature branch → confirm and check the matching `.specify/features/{prefix}-*` directory exists. Not on one → warn ("Feature branches look like 001-feature-name") and recommend creating one, but **do not block** — the developer may proceed deliberately. No git repo → skip with a warning. ## Step 2 — Load context Read the spec, `dev-findings.md` (if present), and the corresponding epic entry in `docs/product/epics.md`. ## Step 3 — Phase 0: resolve dev findings For each HIGH finding in `dev-findings.md`: propose a concrete resolution (data model definition, technical constraint, threshold) and document it in a **Phase 0: Pre-Planning Decisions** section of the plan. A finding that needs human input gets flagged explicitly — never silently skipped. ## Step 4 — Write the implementation plan Write `.specify/features/{slug}/impl-plan.md` — implementation-agnostic (*what* and *why*; the *how* happens during the build): - **Phase 0 — Outline & research**: what's in Phase 1, wha