Add managed command checkpoints requiring fresh human approval (#58045)

## Why

Managed command policies need to require a human decision independently of automatic review, hook allowances, and saved approvals.

## What changed

- Support `decision = "prompt-user"` in managed `requirements.toml` prefix rules, requiring a fresh, one-time human decision for matching commands.
- Add experimental `humanCommand` approval requests for clients advertising both `experimentalApi` and `requiredHumanApproval`. Accept only `accept`, `decline`, or `cancel`; reject commands when no capable client is available.
- Restrict responses to capable clients that received the request, and replay pending prompts to compatible clients on reconnect.
- Enable the capability in the TUI and update protocol schemas and client bindings.

## Testing

Add coverage for fresh decisions overriding saved allowances, hook allowances, and automatic review, plus child-thread approval routing and rejection of responses from incompatible or unrelated clients.

GitOrigin-RevId: 0b95ff6aab7f8a04b7298c8a4329d1fddf6a603e

codex-rs/app-server-protocol/src/protocol/v2/item.rs

@@ -1644,6 +1644,10 @@ v2_enum_from_core! {
     pub enum CommandExecutionApprovalKind from CoreExecApprovalKind {
         #[default]
         Command,
+        /// A managed checkpoint requiring a fresh human decision. Only `accept`, `decline`, and
+        /// `cancel` are valid. Requires the `requiredHumanApproval` initialize capability.
+        /// This prompt does not itself start a command execution item.
+        HumanCommand,
         WriteStdin,
     }
 }