Add check-skills: verify skill symlinks match source repo

Compares installed skill symlinks against the source directory,
reporting missing, stale, and orphan entries.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

scripts/check-skills

@@ -0,0 +1,119 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+# Check which skills from the source repo are missing from the active Claude profile.
+
+DEFAULT_SKILLS_REPO="$HOME/dev/claude/projects/custom-claude-skills/skills"
+
+usage() {
+    cat <<'EOF'
+Usage: check-skills [OPTIONS] [SKILLS_REPO]
+
+Check which skills from the custom-claude-skills repository are missing
+from the active Claude Code profile's skills directory.
+
+Arguments:
+  SKILLS_REPO    Path to skills source directory
+                 (default: ~/dev/claude/projects/custom-claude-skills/skills)
+
+Options:
+  --profile DIR  Override Claude profile directory
+                 (default: $CLAUDE_CONFIG_DIR or ~/.claude)
+  --dryrun, -n   Accepted for convention compliance (script is read-only)
+  --help, -h     Show this help
+EOF
+}
+
+# Colours
+GREEN='\033[0;32m'
+YELLOW='\033[1;33m'
+CYAN='\033[0;36m'
+RED='\033[0;31m'
+BOLD='\033[1m'
+NC='\033[0m'
+
+# Parse args
+profile_dir=""
+skills_repo=""
+
+while [[ $# -gt 0 ]]; do
+    case "$1" in
+        --profile) profile_dir="$2"; shift 2 ;;
+        --dryrun|-n) shift ;;
+        --help|-h) usage; exit 0 ;;
+        -*) echo "Unknown option: $1" >&2; usage >&2; exit 1 ;;
+        *) skills_repo="$1"; shift ;;
+    esac
+done
+
+skills_repo="${skills_repo:-$DEFAULT_SKILLS_REPO}"
+profile_dir="${profile_dir:-${CLAUDE_CONFIG_DIR:-$HOME/.claude}}"
+profile_skills="$profile_dir/skills"
+
+# Validate source
+if [[ ! -d "$skills_repo" ]]; then
+    echo -e "${RED}ERROR${NC} Skills source directory not found: $skills_repo" >&2
+    exit 1
+fi
+
+# Display paths (use ~ shorthand for readability)
+display_profile="${profile_skills/#$HOME/~}"
+display_source="${skills_repo/#$HOME/~}"
+echo -e "${BOLD}Profile:${NC} $display_profile"
+echo -e "${BOLD}Source:${NC}  $display_source"
+echo ""
+
+linked=0
+missing=0
+stale=0
+orphan=0
+
+# Check each source skill
+for skill_dir in "$skills_repo"/*/; do
+    [[ -d "$skill_dir" ]] || continue
+    [[ -f "$skill_dir/SKILL.md" ]] || continue
+
+    skill_name="$(basename "$skill_dir")"
+    target="$profile_skills/$skill_name"
+
+    if [[ -L "$target" ]]; then
+        actual="$(readlink -f "$target" 2>/dev/null || echo "BROKEN")"
+        expected="$(readlink -f "$skill_dir")"
+        if [[ "$actual" == "$expected" ]]; then
+            echo -e "  ${GREEN}LINKED${NC}   $skill_name"
+            linked=$((linked + 1))
+        else
+            echo -e "  ${YELLOW}STALE${NC}    $skill_name (points to $actual)"
+            stale=$((stale + 1))
+        fi
+    elif [[ -e "$target" ]]; then
+        echo -e "  ${YELLOW}STALE${NC}    $skill_name (non-symlink exists)"
+        stale=$((stale + 1))
+    else
+        echo -e "  ${YELLOW}MISSING${NC}  $skill_name"
+        missing=$((missing + 1))
+    fi
+done
+
+# Check for orphans in profile
+if [[ -d "$profile_skills" ]]; then
+    for entry in "$profile_skills"/*/; do
+        [[ -d "$entry" || -L "$entry" ]] || continue
+        entry_name="$(basename "$entry")"
+        if [[ ! -d "$skills_repo/$entry_name" ]]; then
+            echo -e "  ${CYAN}ORPHAN${NC}   $entry_name (not in source repo)"
+            orphan=$((orphan + 1))
+        fi
+    done
+fi
+
+echo ""
+echo -e "Summary: ${GREEN}$linked linked${NC}, ${YELLOW}$missing missing${NC}, ${YELLOW}$stale stale${NC}, ${CYAN}$orphan orphan${NC}"
+
+if [[ $missing -gt 0 || $stale -gt 0 ]]; then
+    echo ""
+    echo "Run 'install.sh' from the custom-claude-skills repo to fix missing/stale skills."
+    exit 1
+fi
+
+exit 0