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)
 // ---------------------------------------------------------------------------