Resolve saved Daybreak choices for each subagent turn (#60773)

## Why

A subagent can use a different model from its parent, with different supported access programs. Saved Daybreak choices need to resolve against the subagent's model and remain consistent throughout its turn, including compaction.

## What changed

- Resolve saved choices before native subagent turns start, preserving explicit turn overrides and applying saved toggles on later turns.
- Distinguish inherited parent programs from explicit child selections. Adapt inherited Daybreak Blue/Red selections to the child model while retaining the saved choice as the default for later turns and nested subagents.
- Validate the account associated with automatic selections and reject incompatible saved choices before sending model requests, while retaining rejected user input in conversation history.
- Require model changes to wait until the next turn when a saved Daybreak choice is present.

## Testing

Add coverage for both multi-agent spawn versions, model-specific selection, automatic compaction, WebSocket response reuse, account changes, unsupported choices, and rejected-input persistence across resume.

GitOrigin-RevId: 11971138d656600d9878187225e4d33217e68ad4

codex-rs/core/src/tools/handlers/multi_agents/spawn.rs

@@ -6,10 +6,12 @@ use crate::agent::child_config::SpawnConfigVersion;
 use crate::agent::child_config::prepare_agent_spawn_config;
 use crate::agent::control::render_input_preview;
 use crate::agent::exceeds_thread_spawn_depth_limit;
+use crate::agent::helper_daybreak::turn::explicit_program_for_spawn;
 use crate::agent::next_thread_spawn_depth;
 use crate::agent::role::DEFAULT_ROLE_NAME;
 use crate::agent::types::SpawnAgentForkMode;
 use crate::agent::types::SpawnAgentOptions;
+use crate::agent::types::SpawnProgramSource;
 use crate::tools::handlers::multi_agents_spec::SpawnAgentToolOptions;
 use crate::tools::handlers::multi_agents_spec::create_spawn_agent_tool_v1;
 use codex_protocol::protocol::MultiAgentVersion;
@@ -134,7 +136,8 @@ async fn handle_spawn_agent(
                 environments: Some(step_context.inherited_environments.clone()),
                 disabled_plugin_ids: Some(turn.disabled_plugin_ids.clone()),
                 multi_agent_v2_usage_hints: None,
-                cyber_access_program: turn.cyber_access_program,
+                cyber_access_program: explicit_program_for_spawn(turn),
+                cyber_access_program_source: SpawnProgramSource::ParentTurn,
             },
         })
         .await