Use collaboration mode masks without mutating base settings (#9806)

Keep an unmasked base collaboration mode and apply the active mask on
demand. Simplify the TUI mask helpers and update tests/docs to match the
mask contract.

codex-rs/core/src/models_manager/collaboration_mode_presets.rs

@@ -1,6 +1,5 @@
-use codex_protocol::config_types::CollaborationMode;
+use codex_protocol::config_types::CollaborationModeMask;
 use codex_protocol::config_types::ModeKind;
-use codex_protocol::config_types::Settings;
 use codex_protocol::openai_models::ReasoningEffort;
 
 const COLLABORATION_MODE_PLAN: &str = include_str!("../../templates/collaboration_mode/plan.md");
@@ -10,7 +9,7 @@ const COLLABORATION_MODE_PAIR_PROGRAMMING: &str =
 const COLLABORATION_MODE_EXECUTE: &str =
     include_str!("../../templates/collaboration_mode/execute.md");
 
-pub(super) fn builtin_collaboration_mode_presets() -> Vec<CollaborationMode> {
+pub(super) fn builtin_collaboration_mode_presets() -> Vec<CollaborationModeMask> {
     vec![
         plan_preset(),
         code_preset(),
@@ -20,50 +19,46 @@ pub(super) fn builtin_collaboration_mode_presets() -> Vec<CollaborationMode> {
 }
 
 #[cfg(any(test, feature = "test-support"))]
-pub fn test_builtin_collaboration_mode_presets() -> Vec<CollaborationMode> {
+pub fn test_builtin_collaboration_mode_presets() -> Vec<CollaborationModeMask> {
     builtin_collaboration_mode_presets()
 }
 
-fn plan_preset() -> CollaborationMode {
-    CollaborationMode {
-        mode: ModeKind::Plan,
-        settings: Settings {
-            model: "gpt-5.2-codex".to_string(),
-            reasoning_effort: Some(ReasoningEffort::High),
-            developer_instructions: Some(COLLABORATION_MODE_PLAN.to_string()),
-        },
+fn plan_preset() -> CollaborationModeMask {
+    CollaborationModeMask {
+        name: "Plan".to_string(),
+        mode: Some(ModeKind::Plan),
+        model: Some("gpt-5.2-codex".to_string()),
+        reasoning_effort: Some(Some(ReasoningEffort::High)),
+        developer_instructions: Some(Some(COLLABORATION_MODE_PLAN.to_string())),
     }
 }
 
-fn code_preset() -> CollaborationMode {
-    CollaborationMode {
-        mode: ModeKind::Code,
-        settings: Settings {
-            model: "gpt-5.2-codex".to_string(),
-            reasoning_effort: Some(ReasoningEffort::Medium),
-            developer_instructions: Some(COLLABORATION_MODE_CODE.to_string()),
-        },
+fn code_preset() -> CollaborationModeMask {
+    CollaborationModeMask {
+        name: "Code".to_string(),
+        mode: Some(ModeKind::Code),
+        model: Some("gpt-5.2-codex".to_string()),
+        reasoning_effort: Some(Some(ReasoningEffort::Medium)),
+        developer_instructions: Some(Some(COLLABORATION_MODE_CODE.to_string())),
     }
 }
 
-fn pair_programming_preset() -> CollaborationMode {
-    CollaborationMode {
-        mode: ModeKind::PairProgramming,
-        settings: Settings {
-            model: "gpt-5.2-codex".to_string(),
-            reasoning_effort: Some(ReasoningEffort::Medium),
-            developer_instructions: Some(COLLABORATION_MODE_PAIR_PROGRAMMING.to_string()),
-        },
+fn pair_programming_preset() -> CollaborationModeMask {
+    CollaborationModeMask {
+        name: "Pair Programming".to_string(),
+        mode: Some(ModeKind::PairProgramming),
+        model: Some("gpt-5.2-codex".to_string()),
+        reasoning_effort: Some(Some(ReasoningEffort::Medium)),
+        developer_instructions: Some(Some(COLLABORATION_MODE_PAIR_PROGRAMMING.to_string())),
     }
 }
 
-fn execute_preset() -> CollaborationMode {
-    CollaborationMode {
-        mode: ModeKind::Execute,
-        settings: Settings {
-            model: "gpt-5.2-codex".to_string(),
-            reasoning_effort: Some(ReasoningEffort::High),
-            developer_instructions: Some(COLLABORATION_MODE_EXECUTE.to_string()),
-        },
+fn execute_preset() -> CollaborationModeMask {
+    CollaborationModeMask {
+        name: "Execute".to_string(),
+        mode: Some(ModeKind::Execute),
+        model: Some("gpt-5.2-codex".to_string()),
+        reasoning_effort: Some(Some(ReasoningEffort::High)),
+        developer_instructions: Some(Some(COLLABORATION_MODE_EXECUTE.to_string())),
     }
 }

codex-rs/core/src/models_manager/manager.rs

@@ -14,7 +14,7 @@ use crate::models_manager::model_presets::builtin_model_presets;
 use codex_api::ModelsClient;
 use codex_api::ReqwestTransport;
 use codex_app_server_protocol::AuthMode;
-use codex_protocol::config_types::CollaborationMode;
+use codex_protocol::config_types::CollaborationModeMask;
 use codex_protocol::openai_models::ModelInfo;
 use codex_protocol::openai_models::ModelPreset;
 use codex_protocol::openai_models::ModelsResponse;
@@ -91,7 +91,7 @@ impl ModelsManager {
     /// List collaboration mode presets.
     ///
     /// Returns a static set of presets seeded with the configured model.
-    pub fn list_collaboration_modes(&self) -> Vec<CollaborationMode> {
+    pub fn list_collaboration_modes(&self) -> Vec<CollaborationModeMask> {
         builtin_collaboration_mode_presets()
     }
 

codex-rs/core/src/thread_manager.rs

@@ -19,7 +19,7 @@ use crate::rollout::RolloutRecorder;
 use crate::rollout::truncation;
 use crate::skills::SkillsManager;
 use codex_protocol::ThreadId;
-use codex_protocol::config_types::CollaborationMode;
+use codex_protocol::config_types::CollaborationModeMask;
 use codex_protocol::openai_models::ModelPreset;
 use codex_protocol::protocol::InitialHistory;
 use codex_protocol::protocol::McpServerRefreshConfig;
@@ -158,7 +158,7 @@ impl ThreadManager {
             .await
     }
 
-    pub fn list_collaboration_modes(&self) -> Vec<CollaborationMode> {
+    pub fn list_collaboration_modes(&self) -> Vec<CollaborationModeMask> {
         self.state.models_manager.list_collaboration_modes()
     }