fix(domain,application,infrastructure,backend,app-tauri,frontend): Stop demande agent préserve la conversation ouverte — arrêt sans fermeture/clôture du chat, états cohérents après cancel sur les 3 adapters de session, cellule et workstate synchronisés — #343 (QA verte)

crates/backend/src/dto.rs

@@ -12,16 +12,19 @@ use serde_json::Value;
 
 use application::{
     AgentBackgroundTaskState, AgentTicketState, AppError, AppExitWorkGuardDetail,
-    AppExitWorkGuardState, AttachLiveAgentOutput, BackgroundTaskKindLabel, CellAgentPresentation,
-    ConversationPreviewStatus, ConversationTurnWorkPreview, ConversationWorkSummary,
-    CreateProjectInput, CreateProjectOutput, ExecuteSlashCommandOutput, GitGraphOutput,
-    HealthInput, HealthReport, LayoutKind, ListProjectsOutput, ListSlashCommandsOutput,
-    LiveRuntimeState, LiveSessionKind, LiveSessionSnapshot, OpenProjectOutput, ProjectWorkState,
-    RestartCellAgentRuntimeOutput, RestoreOpenProjectFailure, RestoreOpenProjectsOutput,
-    SlashCommandEffect, StopLiveAgentOutput, TicketWorkSource, TicketWorkStatus, TurnPage,
-    TurnSource, TurnView,
+    AppExitWorkGuardState, AttachLiveAgentOutput, BackgroundTaskKindLabel, CancelAgentChatOutput,
+    CellAgentPresentation, ConversationPreviewStatus, ConversationTurnWorkPreview,
+    ConversationWorkSummary, CreateProjectInput, CreateProjectOutput, ExecuteSlashCommandOutput,
+    GitGraphOutput, HealthInput, HealthReport, LayoutKind, ListProjectsOutput,
+    ListSlashCommandsOutput, LiveRuntimeState, LiveSessionKind, LiveSessionSnapshot,
+    OpenProjectOutput, ProjectWorkState, RestartCellAgentRuntimeOutput, RestoreOpenProjectFailure,
+    RestoreOpenProjectsOutput, SlashCommandEffect, StopLiveAgentOutput, TicketWorkSource,
+    TicketWorkStatus, TurnPage, TurnSource, TurnView,
+};
+use domain::ports::{
+    CancelCurrentTurnOutcome, ReplyProgress, ReplyProgressKind, ReplyProgressSource,
+    ReplyProgressStage,
 };
-use domain::ports::{ReplyProgress, ReplyProgressKind, ReplyProgressSource, ReplyProgressStage};
 use domain::{
     AgentBusyState, PageCursor, PageDirection, Project, ProjectId, ProjectSystemPermissions,
     ResolvedAgentSystemPermissions, SlashCommand, SystemPermissionSet, TurnRole,
@@ -4763,6 +4766,45 @@ pub struct StopLiveAgentResponseDto {
     pub already_stopped: bool,
 }
 
+/// Response DTO for a non-destructive `cancel_agent_chat` request.
+#[derive(Debug, Clone, Serialize)]
+#[serde(rename_all = "camelCase")]
+pub struct CancelAgentChatResponseDto {
+    /// Stable structured session, still live after the operation.
+    pub session_id: String,
+    /// Idempotent turn-level result.
+    pub outcome: CancelAgentChatOutcomeDto,
+}
+
+/// Public cancellation outcomes, distinct from a missing-session error.
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize)]
+#[serde(rename_all = "camelCase")]
+pub enum CancelAgentChatOutcomeDto {
+    /// A running request was cancelled.
+    Cancelled,
+    /// That request had already been cancelled.
+    AlreadyCancelled,
+    /// The live session currently had no running request.
+    AlreadyCompleted,
+}
+
+impl From<CancelAgentChatOutput> for CancelAgentChatResponseDto {
+    fn from(output: CancelAgentChatOutput) -> Self {
+        Self {
+            session_id: output.session_id.to_string(),
+            outcome: match output.outcome {
+                CancelCurrentTurnOutcome::Cancelled => CancelAgentChatOutcomeDto::Cancelled,
+                CancelCurrentTurnOutcome::AlreadyCancelled => {
+                    CancelAgentChatOutcomeDto::AlreadyCancelled
+                }
+                CancelCurrentTurnOutcome::AlreadyCompleted => {
+                    CancelAgentChatOutcomeDto::AlreadyCompleted
+                }
+            },
+        }
+    }
+}
+
 /// One stopped runtime in an agent-level stop response.
 #[derive(Debug, Clone, Serialize)]
 #[serde(rename_all = "camelCase")]
@@ -6298,6 +6340,22 @@ mod tests {
     use serde_json::json;
     use uuid::Uuid;
 
+    #[test]
+    fn cancel_agent_chat_outcomes_are_stable_camel_case_values() {
+        let response = CancelAgentChatResponseDto::from(CancelAgentChatOutput {
+            session_id: domain::SessionId::from_uuid(Uuid::from_u128(343)),
+            outcome: CancelCurrentTurnOutcome::AlreadyCancelled,
+        });
+
+        assert_eq!(
+            serde_json::to_value(response).unwrap(),
+            json!({
+                "sessionId": Uuid::from_u128(343).to_string(),
+                "outcome": "alreadyCancelled"
+            })
+        );
+    }
+
     #[test]
     fn settings_dtos_are_additive_and_validate_language_and_icon_contracts() {
         let legacy_user: UserSettingsDto = serde_json::from_value(json!({})).unwrap();

crates/backend/src/lib.rs

@@ -17,21 +17,21 @@ use application::{
     AgentWakeService, AllocateManagedTemp, AppError, AssignIssueAgent, AssignSkillToAgent,
     AssignTicketToSprint, AssignedSkillResolver, AttachLiveAgent, AuthenticateSession,
     BackgroundCommandArchive, BulkDeleteIssues, BulkUpdateIssuePriority, BulkUpdateIssueStatus,
-    CancelBackgroundTask, ChangeAgentProfile, CheckEmbedderSuggestion, ClearChatDraft,
-    CloneOpenCodeProfileFromSeed, CloneProfileFromSeed, CloseProject, CloseTab, CloseTerminal,
-    CloseTicketAssistant, ConfigureProfiles, ContextGuardUseCases, CreateAgentFromScratch,
-    CreateAgentFromTemplate, CreateIssue, CreateLayout, CreateMemory, CreateProject, CreateSkill,
-    CreateSprint, CreateTemplate, DeleteAgent, DeleteEmbedderProfile, DeleteIssue, DeleteLayout,
-    DeleteMemory, DeleteModelArtifact, DeleteModelServer, DeleteProfile, DeleteSkill, DeleteSprint,
-    DeleteTemplate, DescribeEmbedderEngines, DetectAgentDrift, DetectProfiles,
-    DismissEmbedderSuggestion, EnsureLocalModelServer, ExecuteSlashCommand, FirstRunState,
-    GcManagedTemp, GetAppExitWorkGuardState, GetLiveStateLean, GetMemory, GetProjectPermissions,
-    GetProjectSystemPermissions, GetProjectWorkState, GitBranches, GitCheckout, GitCommit,
-    GitGraph, GitInit, GitLog, GitStage, GitStatus, GitUnstage, HarvestMemoryFromTurn,
-    HealthUseCase, ImportChatAttachments, InspectConversation, InstallPluginFromArchive,
-    InstallPluginFromDirectory, JsonPluginManifestValidator, LaunchAgent, LaunchAgentInput,
-    LinkIssues, ListAgents, ListAgentsInput, ListClaudeModels, ListCodexModels, ListDevices,
-    ListEmbedderProfiles, ListIssues, ListLayouts, ListMemories, ListModelServers,
+    CancelAgentChat, CancelBackgroundTask, ChangeAgentProfile, CheckEmbedderSuggestion,
+    ClearChatDraft, CloneOpenCodeProfileFromSeed, CloneProfileFromSeed, CloseProject, CloseTab,
+    CloseTerminal, CloseTicketAssistant, ConfigureProfiles, ContextGuardUseCases,
+    CreateAgentFromScratch, CreateAgentFromTemplate, CreateIssue, CreateLayout, CreateMemory,
+    CreateProject, CreateSkill, CreateSprint, CreateTemplate, DeleteAgent, DeleteEmbedderProfile,
+    DeleteIssue, DeleteLayout, DeleteMemory, DeleteModelArtifact, DeleteModelServer, DeleteProfile,
+    DeleteSkill, DeleteSprint, DeleteTemplate, DescribeEmbedderEngines, DetectAgentDrift,
+    DetectProfiles, DismissEmbedderSuggestion, EnsureLocalModelServer, ExecuteSlashCommand,
+    FirstRunState, GcManagedTemp, GetAppExitWorkGuardState, GetLiveStateLean, GetMemory,
+    GetProjectPermissions, GetProjectSystemPermissions, GetProjectWorkState, GitBranches,
+    GitCheckout, GitCommit, GitGraph, GitInit, GitLog, GitStage, GitStatus, GitUnstage,
+    HarvestMemoryFromTurn, HealthUseCase, ImportChatAttachments, InspectConversation,
+    InstallPluginFromArchive, InstallPluginFromDirectory, JsonPluginManifestValidator, LaunchAgent,
+    LaunchAgentInput, LinkIssues, ListAgents, ListAgentsInput, ListClaudeModels, ListCodexModels,
+    ListDevices, ListEmbedderProfiles, ListIssues, ListLayouts, ListMemories, ListModelServers,
     ListOpenCodeProviders, ListPluginRuntimeContributions, ListPlugins, ListProfiles,
     ListProjectFiles, ListProjectPluginSettings, ListProjects, ListResumableAgents, ListSkills,
     ListSlashCommands, ListSprints, ListTemplates, LiveAgentRegistry, LiveSessions,
@@ -2207,6 +2207,8 @@ pub struct BackendCore {
     /// `LaunchAgent`/`ChangeAgentProfile` ; consommé par les commandes de chat (D4)
     /// pour résoudre la session vivante d'un `sessionId` et l'arrêter à la fermeture.
     pub structured_sessions: Arc<StructuredSessions>,
+    /// Non-destructive cancellation of the current structured chat request.
+    pub cancel_agent_chat: Arc<CancelAgentChat>,
     // --- Agents (L6) ---
     /// Create a project agent from scratch.
     pub create_agent: Arc<CreateAgentFromScratch>,
@@ -2752,6 +2754,7 @@ impl BackendCore {
         // `profile.structured_adapter`. Injectés dans LaunchAgent (routage §17.4) et
         // ChangeAgentProfile (shutdown polymorphe au hot-swap).
         let structured_sessions = Arc::new(StructuredSessions::new());
+        let cancel_agent_chat = Arc::new(CancelAgentChat::new(Arc::clone(&structured_sessions)));
         let live_sessions = Arc::new(LiveSessions::new(
             Arc::clone(&terminal_sessions),
             Arc::clone(&structured_sessions),
@@ -4462,6 +4465,7 @@ impl BackendCore {
             update_agent_mcp_tool_permissions,
             set_agent_mcp_tool_allowed,
             structured_sessions,
+            cancel_agent_chat,
             create_agent,
             list_agents,
             read_agent_context,