feature-implement

/feature-implement

Phase 3 of the develop workflow. Run after /feature-design completes (Phase 2 approved). Phase 4 (implementation execution) continues in /feature-implement-execute.

Before ANY Phase 3-4 work begins, run this verification:

# ══════════════════════════════════════════════════════════════
# PREREQUISITE CHECK: feature-implement (Phase 3-4)
# ══════════════════════════════════════════════════════════════

PROJECT_ROOT=$(git rev-parse --show-toplevel 2>/dev/null || pwd)
PROJECT_ENCODED=$(echo "$PROJECT_ROOT" | sed 's|^/||' | tr '/' '-')

echo "=== Phase 3-4 Prerequisites ==="

# CHECK 1: Determine entry path by need flags
NEEDS_DESIGN="[SESSION_PREFERENCES.need_flags.needs_design]"
echo "needs_design: $NEEDS_DESIGN"

if [ "$NEEDS_DESIGN" = "true" ]; then
  # CHECK 2 (needs_design): Design document must exist
  echo "Required: Design document exists"
  ls ~/.local/spellbook/docs/$PROJECT_ENCODED/plans/*-design.md 2>/dev/null || echo "FAIL: No design document found"

  # CHECK 3 (needs_design): Design review must be complete
  echo "Required: Design review completed"
else
  echo "Zero-flag fast path: no external design required"
  echo "Required: Inline plan confirmed by user (<=5 steps)"
  echo "Invoke /feature-implement-execute and navigate to its '## Phase 4: Implementation' header."
  echo "Skip the Phase 3 design-derived steps. Entering at Phase 4 directly."
fi

# CHECK 4 (all paths): No escape hatch conflict
echo "Verify: escape_hatch routing is consistent with current entry point"

If ANY check fails: STOP. Return to the appropriate phase.

Anti-rationalization: "Simple enough to hold in your head" or "plan as we go" = Pattern 3 (Time Pressure) or Pattern 5 (Competence Assertion). Implementation without a plan must be re-done.

Invariant Principles

1. Design precedes implementation - Never implement without an approved design document and implementation plan
2. Delegate actual work - Main context orchestrates; subagents write code, run tests, perform reviews
3. Quality gates are mandatory - Code review, fact-checking, and green mirage audit after every task; no exceptions
4. Behavior preservation in refactoring - Test verification at every transformation; no behavior changes without approval