add claude specific configuration and instruction

.claude/settings.json

@@ -0,0 +1,23 @@
+{
+  "permissions": {
+    "deny": [
+      "Read(.env*)",
+      "Read(**/*.pem)",
+      "Read(**/*.key)"
+    ]
+  },
+  "hooks": {
+    "PostToolUse": [
+      {
+        "matcher": "Write|Edit|MultiEdit",
+        "hooks": [
+          {
+            "type": "command",
+            "command": "filepath=$(jq -r '.tool_input.file_path // .tool_input.path // empty' /dev/stdin) && [ -n \"$filepath\" ] && pnpm exec prettier --write \"$filepath\" 2>/dev/null && [[ \"$filepath\" =~ \\.(ts|tsx|js|jsx)$ ]] && pnpm exec eslint --fix \"$filepath\" 2>/dev/null || true",
+            "timeout": 25
+          }
+        ]
+      }
+    ]
+  }
+}