Function getCompoundCommandPrefixesStatic

src/utils/powershell/staticPrefix.ts:204–284

(
  command: string,
  excludeSubcommand?: (element: ParsedCommandElement) => boolean,
)

 * because BashTool.isReadOnly works from regex/patterns, not parsed AST.
 */
export async function getCompoundCommandPrefixesStatic(
  command: string,
  excludeSubcommand?: (element: ParsedCommandElement) => boolean,
): Promise<string[]> {
  const parsed = await parsePowerShellCommand(command)
  if (!parsed.valid) {
    return []
  }

  const commands = getAllCommands(parsed).filter(
    cmd => cmd.elementType === 'CommandAst',
  )

  // Single command — no compound collapse needed.
  if (commands.length <= 1) {
    const prefix = commands[0]
      ? await extractPrefixFromElement(commands[0])
      : null
    return prefix ? [prefix] : []
  }

  const prefixes: string[] = []
  for (const cmd of commands) {
    if (excludeSubcommand?.(cmd)) {
      continue
    }
    const prefix = await extractPrefixFromElement(cmd)
    if (prefix) {
      prefixes.push(prefix)
    }
  }

  if (prefixes.length === 0) {
    return []
  }

  // Group by root command (first word) and collapse each group via
  // word-aligned longest common prefix. `npm run test` + `npm run lint`
  // → `npm run`. But NEVER collapse down to a bare subcommand-aware root:
  // `git add` + `git commit` would LCP to `git`, which extractPrefixFromElement
  // explicitly refuses as too broad (line ~119). Collapsing through that gate
  // would suggest PowerShell(git:*) → auto-allows git push --force forever.
  // When LCP yields a bare subcommand-aware root, drop the group entirely
  // rather than suggest either the too-broad root or N un-collapsed rules.
  //
  // Bash's getCompoundCommandPrefixesStatic has this same collapse without
  // the guard (src/utils/bash/prefix.ts:360-365) — that's a separate fix.
  //
  // Grouping and word-comparison are case-insensitive (PowerShell is
  // case-insensitive: Git === git, Get-Process === get-process). The Map key
  // is lowercased; the emitted prefix keeps the first-seen casing.
  const groups = new Map<string, string[]>()
  for (const prefix of prefixes) {
    const root = prefix.split(' ')[0]!
    const key = root.toLowerCase()
    const group = groups.get(key)
    if (group) {
      group.push(prefix)