harden sandbox escape vectors for bash disabled/restricted modes (#257)

* harden sandbox escape vectors for bash disabled/restricted modes

block git config injection (-c flag as subcommand), dangerous subcommands
(config, submodule, rebase, bisect), code-executing arg flags (--exec,
--extcmd), .gitattributes/.gitmodules writes, and package lifecycle scripts.
add retry logic to test runner for transient failures. add security unit
tests and adhoc attack tests.

Co-authored-by: Cursor <cursoragent@cursor.com>

* only filter subcommands in nobash, remove nobash from ui

* use regex matching

* iterate on tests

* simplify githooks

---------

Co-authored-by: Cursor <cursoragent@cursor.com>

prep/types.ts

@@ -24,8 +24,13 @@ export interface UnknownLanguagePrepResult extends PrepResultBase {
 
 export type PrepResult = NodePrepResult | PythonPrepResult | UnknownLanguagePrepResult;
 
+export type PrepOptions = {
+  /** when true, lifecycle scripts (postinstall, etc.) are suppressed */
+  ignoreScripts: boolean;
+};
+
 export interface PrepDefinition {
   name: string;
   shouldRun: () => Promise<boolean> | boolean;
-  run: () => Promise<PrepResult>;
+  run: (options: PrepOptions) => Promise<PrepResult>;
 }