fix(lint): flatten multi-line frontmatter descriptions before Vale runs

Vale's text.frontmatter.description scope silently stops matching once
the description is a YAML block scalar spanning 2+ physical lines —
the style used by most skills/agents in this repo. scripts/vale-wrap.sh
flattens the description to one line in a scratch copy (preserving the
repo-relative path and total line count) before invoking real vale, and
both audit skills plus the pre-commit hook now call it instead of vale
directly. Also tightens the pre-commit hook's file glob to single path
segments so it can't cross into docs/research examples or asset
templates the way the audit skills' scoped invocations already avoid.

Addresses PR #85 review feedback.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01FxG5T8EJDgkABXxuneuFfn

tests/test-vale-wrap.sh

@@ -0,0 +1,83 @@
+#!/usr/bin/env bash
+# Regression test for scripts/vale-wrap.sh: Vale's `text.frontmatter.description`
+# NLP scope silently stops matching when the description value is a YAML block
+# scalar spanning 2+ physical lines. vale-wrap.sh flattens it to one line before
+# handing off to the real vale binary — this asserts that actually happens.
+set -euo pipefail
+
+REPO_ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+SCRIPT="$REPO_ROOT/scripts/vale-wrap.sh"
+PASS=0
+FAIL=0
+
+pass() { echo "  PASS: $1"; PASS=$((PASS + 1)); }
+fail() { echo "  FAIL: $1"; FAIL=$((FAIL + 1)); }
+
+if ! command -v vale &>/dev/null; then
+  echo "vale is not installed — skipping (matches skill-audit/agent-audit's own fallback behavior)"
+  exit 0
+fi
+
+make_fixture() {
+  local dir desc_lines file
+  dir="$(mktemp -d)"
+  (cd "$dir" && git init -q)
+  mkdir -p "$dir/plugins/testplugin/skills/zzzskill"
+  desc_lines="$1"
+  file="$dir/plugins/testplugin/skills/zzzskill/SKILL.md"
+  {
+    echo "---"
+    echo "name: zzzskill"
+    echo "description: >"
+    for ((i = 1; i <= desc_lines; i++)); do
+      echo "  Line $i mentions helps with and utilize, plus a colon: like this."
+    done
+    echo "---"
+    echo ""
+    echo "Body."
+  } > "$file"
+  echo "$dir"
+}
+
+# --- 1. A known-bad single-line description is caught (sanity check on Vale itself) ---
+echo ""
+echo "--- catches vague wording in a single-line description ---"
+FIXTURE1="$(make_fixture 1)"
+trap 'rm -rf "$FIXTURE1"' EXIT
+if (cd "$FIXTURE1" && bash "$SCRIPT" --config "$REPO_ROOT/.vale.ini" \
+  plugins/testplugin/skills/zzzskill/SKILL.md) | grep -q "VagueWording"; then
+  pass "flags vague wording when description is a single physical line"
+else
+  fail "did not flag known-bad single-line description"
+fi
+
+# --- 2. The same known-bad wording across 2+ physical lines is still caught ---
+echo ""
+echo "--- catches vague wording in a multi-line folded description ---"
+FIXTURE2="$(make_fixture 2)"
+trap 'rm -rf "$FIXTURE1" "$FIXTURE2"' EXIT
+if (cd "$FIXTURE2" && bash "$SCRIPT" --config "$REPO_ROOT/.vale.ini" \
+  plugins/testplugin/skills/zzzskill/SKILL.md) | grep -q "VagueWording"; then
+  pass "flags vague wording when description spans 2+ physical lines"
+else
+  fail "silently missed known-bad wording in a multi-line description — the bug this test guards against"
+fi
+
+# --- 3. Line count is preserved so unrelated report line numbers don't shift ---
+echo ""
+echo "--- preserves total line count when flattening ---"
+FIXTURE3="$(make_fixture 3)"
+trap 'rm -rf "$FIXTURE1" "$FIXTURE2" "$FIXTURE3"' EXIT
+ORIG_LINES=$(wc -l < "$FIXTURE3/plugins/testplugin/skills/zzzskill/SKILL.md")
+OUT=$(cd "$FIXTURE3" && bash "$SCRIPT" --config "$REPO_ROOT/.vale.ini" \
+  plugins/testplugin/skills/zzzskill/SKILL.md 2>&1 || true)
+MAX_LINE=$(echo "$OUT" | grep -oE '^[[:space:]]*[0-9]+:[0-9]+' | tr -d '[:space:]' | cut -d: -f1 | sort -n | tail -1)
+if [[ -n "$MAX_LINE" ]] && (( MAX_LINE <= ORIG_LINES )); then
+  pass "reported line numbers stay within the original file's line count"
+else
+  fail "reported line number ($MAX_LINE) exceeds original file line count ($ORIG_LINES)"
+fi
+
+echo ""
+echo "Results: $PASS passed, $FAIL failed"
+[[ $FAIL -eq 0 ]]