Add Kiro steering files, hooks, and scripts (#812)

Co-authored-by: Sungmin Hong <hsungmin@amazon.com>

.kiro/scripts/format.sh

@@ -0,0 +1,70 @@
+#!/bin/bash
+# ─────────────────────────────────────────────────────────────
+# Format — auto-format a file using detected formatter
+# Detects: biome or prettier
+# Used by: .kiro/hooks/auto-format.json (fileEdited)
+# ─────────────────────────────────────────────────────────────
+
+set -o pipefail
+
+# ── Validate input ───────────────────────────────────────────
+if [ -z "$1" ]; then
+  echo "Usage: format.sh <file>"
+  echo "Example: format.sh src/index.ts"
+  exit 1
+fi
+
+FILE="$1"
+
+if [ ! -f "$FILE" ]; then
+  echo "Error: File not found: $FILE"
+  exit 1
+fi
+
+# ── Detect formatter ─────────────────────────────────────────
+detect_formatter() {
+  if [ -f "biome.json" ] || [ -f "biome.jsonc" ]; then
+    echo "biome"
+  elif [ -f ".prettierrc" ] || [ -f ".prettierrc.js" ] || [ -f ".prettierrc.json" ] || [ -f ".prettierrc.yml" ] || [ -f "prettier.config.js" ] || [ -f "prettier.config.mjs" ]; then
+    echo "prettier"
+  elif command -v biome &>/dev/null; then
+    echo "biome"
+  elif command -v prettier &>/dev/null; then
+    echo "prettier"
+  else
+    echo "none"
+  fi
+}
+
+FORMATTER=$(detect_formatter)
+
+# ── Format file ──────────────────────────────────────────────
+case "$FORMATTER" in
+  biome)
+    if command -v npx &>/dev/null; then
+      echo "Formatting $FILE with Biome..."
+      npx biome format --write "$FILE"
+      exit $?
+    else
+      echo "Error: npx not found (required for Biome)"
+      exit 1
+    fi
+    ;;
+  
+  prettier)
+    if command -v npx &>/dev/null; then
+      echo "Formatting $FILE with Prettier..."
+      npx prettier --write "$FILE"
+      exit $?
+    else
+      echo "Error: npx not found (required for Prettier)"
+      exit 1
+    fi
+    ;;
+  
+  none)
+    echo "No formatter detected (biome.json, .prettierrc, or installed formatter)"
+    echo "Skipping format for: $FILE"
+    exit 0
+    ;;
+esac