feat(agent): reprise des sessions au redémarrage (B2) — commande + ResumeProjectPanel

- Tauri : commande list_resumable_agents (projectId) + ResumableAgentListDto
  { resumable } / ResumableAgentDto (camelCase, conversationId omis si None),
  câblage state.rs (réutilise stores + ProfileStore, aucun nouveau port).
- Front : gateway listResumableAgents, ResumeProjectPanel monté à l'ouverture
  de projet (opt-in, FR) : Reprendre (launch_agent nodeId+conversationId),
  Nouvelle conversation (setCellConversation(null) puis launch), Ignorer,
  Tout reprendre/ignorer. resumeSupported=false ⇒ « relance à neuf ».
- doc : §15.2 coquille agents→resumable (alignée use case/back/front).

Tests : app-tauri dto 9/9 ; vitest 324 (+10) ; workspace Rust 0 échec. 0 régression.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

crates/app-tauri/src/commands.rs

@@ -16,7 +16,8 @@ use application::{
     DetectAgentDriftInput, GetMemoryInput, GitBranchesInput, GitCheckoutInput, GitCommitInput,
     GitGraphInput, GitInitInput, GitLogInput, GitStagePathInput, GitStatusInput,
     InspectConversationInput, LaunchAgentInput, ListAgentsInput, ListLayoutsInput,
-    ListMemoriesInput, ListSkillsInput, LoadLayoutInput, MutateLayoutInput, OpenProjectInput,
+    ListMemoriesInput, ListResumableAgentsInput, ListSkillsInput, LoadLayoutInput, MutateLayoutInput,
+    OpenProjectInput,
     ReadAgentContextInput, ReadMemoryIndexInput, ReadProjectContextInput, RecallMemoryInput,
     RenameLayoutInput, ResolveMemoryLinksInput, SetActiveLayoutInput, SnapshotRunningAgentsInput,
     SyncAgentWithTemplateInput, UnassignSkillFromAgentInput, UpdateAgentContextInput,
@@ -40,7 +41,7 @@ use crate::dto::{
     LaunchAgentRequestDto, LayoutDto, LayoutOperationDto, ListLayoutsDto, LiveAgentListDto,
     MemoryDto, MemoryIndexDto, MemoryLinksDto, MemoryListDto, OpenTerminalRequestDto, ProfileDto,
     ProfileListDto, ProjectDto, ProjectListDto, ReadAgentContextResponseDto, ReattachResultDto,
-    RecallMemoryRequestDto, RenameLayoutRequestDto, ResizeTerminalRequestDto,
+    RecallMemoryRequestDto, RenameLayoutRequestDto, ResizeTerminalRequestDto, ResumableAgentListDto,
     SaveEmbedderProfileRequestDto, SaveProfileRequestDto, SetActiveLayoutRequestDto, SkillDto,
     SkillListDto, SyncAgentWithTemplateRequestDto, SyncResultDto, TemplateDto, TemplateListDto,
     TerminalClosedDto, TerminalSessionDto, UnassignSkillRequestDto, UpdateAgentContextRequestDto,
@@ -1075,6 +1076,32 @@ pub async fn change_agent_profile(
         .map_err(ErrorDto::from)
 }
 
+/// `list_resumable_agents` — read-only inventory of an open project's resumable
+/// agent cells (§15.2). Each entry carries the agent + its host cell, the CLI
+/// conversation id to resume (absent ⇒ fresh relaunch), the `was_running` flag
+/// frozen at close, and whether the profile can resume a conversation.
+///
+/// Best-effort by contract: an unreadable project/layout/manifest degrades to an
+/// empty list, never an error. Drives the reopen panel, which reuses
+/// `launch_agent` for the actual resume (no new resume command).
+///
+/// # Errors
+/// Returns an [`ErrorDto`] (`INVALID` for a malformed id, `NOT_FOUND` if the
+/// project is unknown, `STORE` on a project-registry failure).
+#[tauri::command]
+pub async fn list_resumable_agents(
+    project_id: String,
+    state: State<'_, AppState>,
+) -> Result<ResumableAgentListDto, ErrorDto> {
+    let project = resolve_project(&project_id, &state).await?;
+    state
+        .list_resumable_agents
+        .execute(ListResumableAgentsInput { project })
+        .await
+        .map(ResumableAgentListDto::from)
+        .map_err(ErrorDto::from)
+}
+
 // ---------------------------------------------------------------------------
 // Templates & sync (L7)
 // ---------------------------------------------------------------------------

crates/app-tauri/src/dto.rs

@@ -1305,6 +1305,72 @@ pub fn parse_agent_id(raw: &str) -> Result<AgentId, ErrorDto> {
         })
 }
 
+// ---------------------------------------------------------------------------
+// Resumable agents (§15.2 — Chantier B2)
+// ---------------------------------------------------------------------------
+
+use application::{ListResumableAgentsOutput, ResumableAgent};
+
+/// One resumable agent cell, as seen by the frontend (§15.2).
+///
+/// Mirrors [`ResumableAgent`]: the agent's identity + its host cell, the CLI
+/// conversation id to resume (absent ⇒ fresh relaunch), the `was_running` flag
+/// frozen at close, and whether the agent's profile can resume a CLI
+/// conversation. `conversationId` is **omitted from the wire when `None`**
+/// (`skip_serializing_if`), so the TypeScript side sees an absent key — not
+/// `null`.
+#[derive(Debug, Clone, Serialize)]
+#[serde(rename_all = "camelCase")]
+pub struct ResumableAgentDto {
+    /// The resumable agent's id (UUID string).
+    pub agent_id: String,
+    /// The agent's display name (resolved from the manifest).
+    pub name: String,
+    /// The host layout leaf where the agent is relaunched/resumed (UUID string).
+    pub node_id: String,
+    /// Persistent CLI conversation id carried by the cell. Absent ⇒ fresh
+    /// relaunch (no history to resume).
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub conversation_id: Option<String>,
+    /// The `agent_was_running` flag frozen at the cell's close.
+    pub was_running: bool,
+    /// `true` when the agent's profile carries a usable resume strategy.
+    pub resume_supported: bool,
+}
+
+impl From<ResumableAgent> for ResumableAgentDto {
+    fn from(r: ResumableAgent) -> Self {
+        Self {
+            agent_id: r.agent_id.to_string(),
+            name: r.name,
+            node_id: r.node_id.to_string(),
+            conversation_id: r.conversation_id,
+            was_running: r.was_running,
+            resume_supported: r.resume_supported,
+        }
+    }
+}
+
+/// Response DTO for `list_resumable_agents` (§15.2).
+#[derive(Debug, Clone, Serialize)]
+#[serde(rename_all = "camelCase")]
+pub struct ResumableAgentListDto {
+    /// The resumable agent cells, in layout-traversal order.
+    pub resumable: Vec<ResumableAgentDto>,
+}
+
+impl From<ListResumableAgentsOutput> for ResumableAgentListDto {
+    fn from(out: ListResumableAgentsOutput) -> Self {
+        Self {
+            resumable: out
+                .resumable
+                .into_iter()
+                .map(ResumableAgentDto::from)
+                .collect(),
+        }
+    }
+}
+
 // ---------------------------------------------------------------------------
 // Templates & sync (L7)
 // ---------------------------------------------------------------------------

crates/app-tauri/src/lib.rs

@@ -127,6 +127,7 @@ pub fn run() {
             commands::delete_agent,
             commands::launch_agent,
             commands::change_agent_profile,
+            commands::list_resumable_agents,
             commands::inspect_conversation,
             commands::create_template,
             commands::update_template,

crates/app-tauri/src/state.rs

@@ -18,7 +18,8 @@ use application::{
     DetectAgentDrift, DetectProfiles, DismissEmbedderSuggestion, FirstRunState, GetMemory,
     GitBranches, GitCheckout, GitCommit, GitGraph, GitInit, GitLog, GitStage, GitStatus,
     GitUnstage, HealthUseCase, InspectConversation, LaunchAgent, ListAgents, ListEmbedderProfiles,
-    ListLayouts, ListMemories, ListProfiles, ListProjects, ListSkills, ListTemplates,
+    ListLayouts, ListMemories, ListProfiles, ListProjects, ListResumableAgents, ListSkills,
+    ListTemplates,
     LiveAgentRegistry, LoadLayout, MoveTabToNewWindow, MutateLayout, OnnxModelView, OpenProject,
     OpenTerminal, OrchestratorService, ReadAgentContext, ReadMemoryIndex, ReadProjectContext,
     RecallMemory, ReferenceProfiles, RenameLayout, ResizeTerminal, ResolveMemoryLinks,
@@ -131,6 +132,9 @@ pub struct AppState {
     pub launch_agent: Arc<LaunchAgent>,
     /// Hot-swap an agent's runtime profile, relaunching its live session in place (§15.1).
     pub change_agent_profile: Arc<ChangeAgentProfile>,
+    /// Read-only inventory of a project's resumable agent cells, for the reopen
+    /// panel (§15.2).
+    pub list_resumable_agents: Arc<ListResumableAgents>,
     /// Best-effort inspection of a conversation (last topic + token indicator)
     /// for the resume popup (T7). Optional/extensible: backed by a `Vec` of
     /// [`domain::ports::SessionInspector`]s; an empty/missing match yields empty
@@ -531,6 +535,15 @@ impl AppState {
             Arc::clone(&events_port),
         ));
 
+        // Read-only inventory of resumable agent cells (§15.2). Reuses the shared
+        // project/fs/context/profile stores already injected above — no new port.
+        let list_resumable_agents = Arc::new(ListResumableAgents::new(
+            Arc::clone(&store_port),
+            Arc::clone(&fs_port),
+            Arc::clone(&contexts_port),
+            Arc::clone(&profile_store_port),
+        ));
+
         // --- Conversation inspection (T7) ---
         // Best-effort, optional, extensible: a `Vec` of SessionInspectors routed
         // by profile. Adding an inspectable CLI = pushing one more adapter here.
@@ -717,6 +730,7 @@ impl AppState {
             delete_agent,
             launch_agent,
             change_agent_profile,
+            list_resumable_agents,
             inspect_conversation,
             project_store,
             create_template,