feat(ctx7): coverage extension — fast-libs single source + reminder hook + executor briefs (BDR-078)

- lib/fast-libs.sh: detect/cache-status verbs, JS+Python manifests,
  7-day cache freshness, LC_ALL=C sort — replaces 3 hardcoded lists
  (ship-feature 0c, init-project 5c, onboard 3.5)
- hooks/ctx7-reminder.sh: once-per-session UserPromptSubmit nudge when
  the project carries fast-libs and .ctx7-cache/ is missing/stale
- find-docs: before-writing-code trigger + cache-first rule; dist is
  machine-owned (gitignored) so the durable patch lives in
  install-plugins.sh STEP ctx7 (idempotent, grep-guarded)
- feater/bugfixer briefs: fast-lib docs rule (fresh cache read, else
  2-topic ctx7 fetch, else NOTES cache miss + proceed)
- tests: lib/tests/fast-libs.test.sh (11 checks); shellcheck + full
  make test green (review-guards 5/0)

lib/fast-libs.sh

@@ -0,0 +1,65 @@
+#!/usr/bin/env bash
+# fast-libs.sh — single source of truth for "fast-moving library" detection.
+#
+# Fast-moving = API churns faster than model training data (React, Next.js,
+# Prisma…) → consult ctx7 (find-docs) before coding against it. Stable techs
+# (C, C++98, POSIX sh, SQL…) never match: no ctx7 needed (BDR-078).
+#
+# Consumers: hooks/ctx7-reminder.sh, /ship-feature STEP 0c, /init-project
+# STEP 5c, /onboard STEP 3.5, feater/bugfixer executor briefs.
+#
+# Verbs:
+#   fast-libs.sh detect [dir]        detected libs, one/line; exit 1 if none
+#   fast-libs.sh cache-status [dir]  fresh|stale|missing; exit 0 only if fresh
+
+set -euo pipefail
+
+# Exact npm dependency keys (unscoped). Anchored full-key match — "react"
+# must not drag react-icons along.
+NPM_EXACT='next|react|react-dom|react-native|expo|prisma|supabase'
+NPM_EXACT+='|drizzle-orm|astro|svelte|vue|nuxt|tailwindcss|vite|next-auth'
+NPM_EXACT+='|motion|framer-motion|ai|openai|langchain|remix|fastify'
+# Scoped npm orgs (@org/…).
+NPM_SCOPED='prisma|supabase|astrojs|sveltejs|tanstack|clerk|anthropic-ai'
+NPM_SCOPED+='|langchain|remix-run|nestjs|tailwindcss'
+# Python distributions (requirements.txt / pyproject.toml).
+PY_LIBS='fastapi|pydantic|sqlalchemy|langchain'
+
+CACHE_MAX_AGE_DAYS=7
+
+npm_fast_libs() { # $1=dir — matching dependency keys, one per line
+  [ -f "$1/package.json" ] || return 0
+  jq -r '((.dependencies // {}) + (.devDependencies // {})) | keys[]' \
+    "$1/package.json" 2>/dev/null \
+    | grep -E "^(${NPM_EXACT})\$|^@(${NPM_SCOPED})/" || true
+}
+
+py_fast_libs() { # $1=dir — matching distributions, one per line
+  grep -hoiE "\b(${PY_LIBS})\b" \
+    "$1/requirements.txt" "$1/pyproject.toml" 2>/dev/null \
+    | tr '[:upper:]' '[:lower:]' | LC_ALL=C sort -u || true
+}
+
+detect() { # $1=dir — union, sorted unique; exit 1 when empty
+  local libs
+  # LC_ALL=C: deterministic order whatever the caller's locale.
+  libs="$(printf '%s\n%s\n' "$(npm_fast_libs "$1")" "$(py_fast_libs "$1")" \
+    | sed '/^$/d' | LC_ALL=C sort -u)"
+  [ -n "$libs" ] || return 1
+  printf '%s\n' "$libs"
+}
+
+cache_status() { # $1=dir — fresh|stale|missing; exit 0 only when fresh
+  [ -d "$1/.ctx7-cache" ] || { echo missing; return 1; }
+  if [ -n "$(find "$1/.ctx7-cache" -name '*.md' \
+      -mtime "-${CACHE_MAX_AGE_DAYS}" -print -quit 2>/dev/null)" ]; then
+    echo fresh; return 0
+  fi
+  echo stale; return 1
+}
+
+case "${1:-}" in
+  detect)       detect "${2:-.}" ;;
+  cache-status) cache_status "${2:-.}" ;;
+  *) echo "usage: fast-libs.sh detect|cache-status [dir]" >&2; exit 2 ;;
+esac