fix(cli): show valid approval policy values in --ask-for-approval help

Fixes bounty issue #1424

The --ask-for-approval flag now displays valid options (untrusted, on-failure,
on-request, never) in the help text using clap's value_parser attribute.
Invalid values are also rejected with a clear error message.

Also fixes formatting issues in the file.

Author: factorydroid

cortex-cli/src/main.rs

@@ -104,7 +104,7 @@ struct InteractiveArgs {
     sandbox_mode: Option<CliSandboxMode>,
 
     /// Configure when the model requires human approval
-    #[arg(long = "ask-for-approval", short = 'a')]
+    #[arg(long = "ask-for-approval", short = 'a', value_parser = ["untrusted", "on-failure", "on-request", "never"])]
     approval_policy: Option<String>,
 
     /// Enable automatic execution without approval prompts.