chore(node-sdk): audit providers claudecode codex cursor gemini

Add plugins/shell-command.ts for the shared quoting and command parsers; runtime status checks go through managed-runtime-status; Codex and Cursor write through managed-transaction.

Claude-Session: https://claude.ai/code/session_01Agoc9bRVE9KL7mmWtey9Vq

src/plugins/shell-command.ts

@@ -0,0 +1,121 @@
+import path from 'node:path';
+
+interface ParsedArgument {
+  readonly value: string;
+  readonly next: number;
+}
+
+export type CommandParts = readonly [executable: string, script: string];
+
+const POSIX_APOSTROPHE = `'"'"'`;
+const POWERSHELL_EXIT_SUFFIX = '; exit $LASTEXITCODE';
+const ENCODED_COMMAND_FLAGS = '-NoLogo -NoProfile -NonInteractive -EncodedCommand';
+
+export function quotePosix(value: string): string {
+  return `'${value.replaceAll("'", POSIX_APOSTROPHE)}'`;
+}
+
+export function quotePowerShell(value: string): string {
+  return `'${value.replaceAll("'", "''")}'`;
+}
+
+export function windowsPowerShellPath(): string {
+  const configuredRoot = process.platform === 'win32' ? process.env.SystemRoot : undefined;
+  const systemRoot = configuredRoot
+    && path.win32.isAbsolute(configuredRoot)
+    && !/["%\r\n]/.test(configuredRoot)
+    ? configuredRoot
+    : 'C:\\Windows';
+  return path.win32.join(systemRoot, 'System32', 'WindowsPowerShell', 'v1.0', 'powershell.exe');
+}
+
+export function powerShellSource(scriptPath: string): string {
+  return `& ${quotePowerShell(process.execPath)} ${quotePowerShell(scriptPath)}${POWERSHELL_EXIT_SUFFIX}`;
+}
+
+export function encodePowerShellSource(scriptPath: string): string {
+  return Buffer.from(powerShellSource(scriptPath), 'utf16le').toString('base64');
+}
+
+export function encodedWindowsCommand(scriptPath: string): string {
+  return `"${windowsPowerShellPath()}" ${ENCODED_COMMAND_FLAGS} ${encodePowerShellSource(scriptPath)}`;
+}
+
+export function isNodeExecutable(filePath: string): boolean {
+  const basename = path.basename(filePath);
+  return basename === 'node' || basename.toLowerCase() === 'node.exe';
+}
+
+export function isPowerShellExecutable(filePath: string): boolean {
+  return path.win32.isAbsolute(filePath)
+    && path.win32.basename(filePath).toLowerCase() === 'powershell.exe';
+}
+
+function readPosixArgument(command: string, start: number): ParsedArgument | undefined {
+  if (command[start] !== "'") return undefined;
+  let value = '';
+  for (let index = start + 1; index < command.length;) {
+    if (command.startsWith(POSIX_APOSTROPHE, index)) {
+      value += "'";
+      index += POSIX_APOSTROPHE.length;
+      continue;
+    }
+    if (command[index] === "'") return { value, next: index + 1 };
+    value += command[index];
+    index += 1;
+  }
+  return undefined;
+}
+
+export function parsePosixCommand(command: string): CommandParts | undefined {
+  const executable = readPosixArgument(command, 0);
+  if (!executable || command[executable.next] !== ' ') return undefined;
+  const script = readPosixArgument(command, executable.next + 1);
+  if (!script || script.next !== command.length) return undefined;
+  return [executable.value, script.value];
+}
+
+function readPowerShellArgument(command: string, start: number): ParsedArgument | undefined {
+  if (command[start] !== "'") return undefined;
+  let value = '';
+  for (let index = start + 1; index < command.length; index += 1) {
+    if (command[index] !== "'") {
+      value += command[index];
+      continue;
+    }
+    if (command[index + 1] === "'") {
+      value += "'";
+      index += 1;
+      continue;
+    }
+    return { value, next: index + 1 };
+  }
+  return undefined;
+}
+
+export function parsePowerShellSource(source: string): CommandParts | undefined {
+  if (!source.startsWith('& ')) return undefined;
+  const executable = readPowerShellArgument(source, 2);
+  if (!executable || source[executable.next] !== ' ') return undefined;
+  const script = readPowerShellArgument(source, executable.next + 1);
+  if (!script || source.slice(script.next) !== POWERSHELL_EXIT_SUFFIX) return undefined;
+  return [executable.value, script.value];
+}
+
+export function decodePowerShellSource(encoded: string): CommandParts | undefined {
+  if (!/^[A-Za-z0-9+/]+={0,2}$/.test(encoded)) return undefined;
+  const buffer = Buffer.from(encoded, 'base64');
+  if (buffer.toString('base64') !== encoded || buffer.length % 2 !== 0) return undefined;
+  return parsePowerShellSource(buffer.toString('utf16le'));
+}
+
+export function parseEncodedWindowsCommand(command: string): CommandParts | undefined {
+  const match = /^"([^"\r\n]+)" -NoLogo -NoProfile -NonInteractive -EncodedCommand ([A-Za-z0-9+/]+={0,2})$/.exec(command);
+  if (!match || !isPowerShellExecutable(match[1])) return undefined;
+  return decodePowerShellSource(match[2]);
+}
+
+export function parseLegacyWindowsCommand(command: string): CommandParts | undefined {
+  const match = /^"([^"\r\n]+)" "([^"\r\n]+)"$/.exec(command);
+  return match ? [match[1], match[2]] : undefined;
+}