Add unified scripts system with find-skills and run

Consolidates skill discovery and adds generic runner for cross-platform compatibility.

Changes:
- Created scripts/find-skills: Unified tool (show all + filter by pattern)
  - Shows descriptions by default
  - Searches personal first, then core (shadowing)
  - Logs searches for gap analysis
  - Bash 3.2 compatible

- Created scripts/run: Generic runner for any skill script
  - Searches personal superpowers first, then core
  - Enables running arbitrary skill scripts without CLAUDE_PLUGIN_ROOT env var
  - Example: scripts/run skills/collaboration/remembering-conversations/tool/search-conversations

- Fixed bash 3.2 compatibility in list-skills, skills-search
  - Replaced associative arrays with newline-delimited lists
  - Works on macOS default bash (3.2) and Linux bash 4+

- Updated all documentation to reference scripts/find-skills
- Removed redundant wrapper scripts

This solves the CLAUDE_PLUGIN_ROOT environment variable issue - scripts
can now be called from anywhere without needing the env var set.

scripts/run

@@ -0,0 +1,55 @@
+#!/usr/bin/env bash
+# Generic runner for skill scripts
+# Searches personal superpowers first, then core plugin
+#
+# Usage: scripts/run <skill-relative-path> [args...]
+# Example: scripts/run skills/collaboration/remembering-conversations/tool/search-conversations "query"
+
+set -euo pipefail
+
+if [[ $# -eq 0 ]]; then
+    cat <<'EOF'
+Usage: scripts/run <skill-relative-path> [args...]
+
+Runs scripts from skills, checking personal superpowers first, then core.
+
+Examples:
+  scripts/run skills/collaboration/remembering-conversations/tool/search-conversations "query"
+  scripts/run skills/getting-started/list-skills
+  scripts/run skills/getting-started/skills-search "pattern"
+
+The script will be found at:
+  1. ~/.config/superpowers/<skill-relative-path> (personal, if exists)
+  2. ${CLAUDE_PLUGIN_ROOT}/<skill-relative-path> (core plugin)
+EOF
+    exit 1
+fi
+
+# Get the script path to run
+SCRIPT_PATH="$1"
+shift  # Remove script path from args, leaving remaining args
+
+# Determine directories
+PERSONAL_SUPERPOWERS_DIR="${PERSONAL_SUPERPOWERS_DIR:-${XDG_CONFIG_HOME:-$HOME/.config}/superpowers}"
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+PLUGIN_ROOT="$(cd "$SCRIPT_DIR/.." && pwd)"
+
+# Try personal superpowers first
+PERSONAL_SCRIPT="${PERSONAL_SUPERPOWERS_DIR}/${SCRIPT_PATH}"
+if [[ -x "$PERSONAL_SCRIPT" ]]; then
+    exec "$PERSONAL_SCRIPT" "$@"
+fi
+
+# Fall back to core plugin
+CORE_SCRIPT="${PLUGIN_ROOT}/${SCRIPT_PATH}"
+if [[ -x "$CORE_SCRIPT" ]]; then
+    exec "$CORE_SCRIPT" "$@"
+fi
+
+# Not found
+echo "Error: Script not found: $SCRIPT_PATH" >&2
+echo "" >&2
+echo "Searched:" >&2
+echo "  $PERSONAL_SCRIPT (personal)" >&2
+echo "  $CORE_SCRIPT (core)" >&2
+exit 1