add comments to everything potentially consumer facing

sdk/base/lib/util/splitCommand.ts

@@ -1,3 +1,17 @@
+/**
+ * Normalizes a command into an argv-style string array.
+ * If given a string, wraps it as `["sh", "-c", command]`.
+ * If given a tuple, returns it as-is.
+ *
+ * @param command - A shell command string or a pre-split argv tuple
+ * @returns An argv-style string array suitable for process execution
+ *
+ * @example
+ * ```ts
+ * splitCommand("echo hello")           // ["sh", "-c", "echo hello"]
+ * splitCommand(["node", "index.js"])   // ["node", "index.js"]
+ * ```
+ */
 export const splitCommand = (
   command: string | [string, ...string[]],
 ): string[] => {