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Own-Property Safe Lookups

When you derive keys (extensions, filenames, paths) from user-controlled input to select behavior or presentation, use *own-property safe lookups* (or `Map`) and fail to a neutral default for unknown keys. This prevents inherited/prototype properties (e.g., `__proto__`, `constructor`, `toString`) from being treated as valid entries.

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When you derive keys (extensions, filenames, paths) from user-controlled input to select behavior or presentation, use own-property safe lookups (or Map) and fail to a neutral default for unknown keys. This prevents inherited/prototype properties (e.g., __proto__, constructor, toString) from being treated as valid entries.

Apply it like this:

type IconSpec = { icon: unknown; className: string };
const BY_EXTENSION: Record<string, IconSpec> = {
  ts: { icon: /*...*/ null, className: "text-sky-600 dark:text-sky-400" },
  // ...
};

function baseName(path: string): string {
  return path.split(/[\\/]/).pop() ?? path;
}

export function safeSpecForPath(path: string): IconSpec {
  const name = baseName(path).toLowerCase();
  const ext = name.includes(".") ? (name.split(".").pop() ?? "").toLowerCase() : "";

  // own-property guard against prototype pollution/inherited keys
  if (Object.hasOwn(BY_EXTENSION, ext)) return BY_EXTENSION[ext];

  // neutral/fail-closed default
  return { icon: null, className: "text-muted-foreground" };
}

Additionally, for security-sensitive settings or permission changes, ensure the UI copy precisely distinguishes what is allowed (e.g., read vs sandboxed command write) and where commands run (background executor vs terminal), since ambiguity can lead users to unsafe assumptions.