reuse-firstlisted

# Reuse-first engineering Default to reusing and following what exists. New code is a liability; the best change is the smallest one that fits the codebase. ## 1. Reuse before building - **Ask the proof-carrying cache first**: `forge reuse query "<what you're about to build>"`. A hit is code this team already generated AND verified — its test/accept evidence travels with it (`forge ledger blame <id>` shows why to trust it): - **EXACT / NEAR hit** → use that artifact; do not regenerate. - **ADAPT hit** → read it, start from it, generate only the delta. - **miss** → build it, then `forge reuse mint "<spec>" --file <path> --ref <test-run>` so the next teammate (or session) gets the hit. - Search the repo next (`grep`/`glob`/serena LSP): is there an existing util, component, hook, service, or pattern that already does this? Extend it. - If not in-repo, is there a maintained library? Vet it with `tech-selector` (current best from Context7 + web + GitHub health) before adding a dependency. - Only write from scratch when reuse genuinely doesn't fit — and say why. ## 2. Follow the codebase's patterns - Match the existing architecture and idioms over any personal preference or textbook pattern. Consistency beats cleverness. - Apply a design pattern only when it removes real duplication or coupling — not for its own sake. Prefer composition over inheritance; keep modules cohesive and loosely coupled; push side effects to the edges. ## 3. Design for reuse + t