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/tests/dto_resumable_agents.rs

@@ -0,0 +1,192 @@
+//! B2 tests for the `list_resumable_agents` DTO contract (ARCHITECTURE §15.2):
+//! - `From<ResumableAgent> for ResumableAgentDto` maps every field, surfaces
+//!   `conversationId` only when present (omitted via `skip_serializing_if` when
+//!   `None`), and serialises ids as strings + camelCase keys.
+//! - `From<ListResumableAgentsOutput> for ResumableAgentListDto` preserves the
+//!   `resumable` list and its order.
+//! - Full + minimal `ResumableAgentDto` serde round-trips on the wire shape.
+
+use app_tauri_lib::dto::{ResumableAgentDto, ResumableAgentListDto};
+use application::{ListResumableAgentsOutput, ResumableAgent};
+use domain::ids::{AgentId, NodeId};
+use uuid::Uuid;
+
+/// Helper: a resumable agent with a conversation id (resume-capable).
+fn full(agent_uuid: u128, node_uuid: u128) -> ResumableAgent {
+    ResumableAgent {
+        agent_id: AgentId::from_uuid(Uuid::from_u128(agent_uuid)),
+        name: "Architect".to_owned(),
+        node_id: NodeId::from_uuid(Uuid::from_u128(node_uuid)),
+        conversation_id: Some("conv-123".to_owned()),
+        was_running: true,
+        resume_supported: true,
+    }
+}
+
+/// Helper: a minimal resumable agent without a conversation id.
+fn minimal(agent_uuid: u128, node_uuid: u128) -> ResumableAgent {
+    ResumableAgent {
+        agent_id: AgentId::from_uuid(Uuid::from_u128(agent_uuid)),
+        name: "Scratch".to_owned(),
+        node_id: NodeId::from_uuid(Uuid::from_u128(node_uuid)),
+        conversation_id: None,
+        was_running: false,
+        resume_supported: false,
+    }
+}
+
+// ---------------------------------------------------------------------------
+// From<ResumableAgent> for ResumableAgentDto — field mapping
+// ---------------------------------------------------------------------------
+
+#[test]
+fn from_resumable_agent_maps_every_field() {
+    let r = full(1, 2);
+    let dto = ResumableAgentDto::from(r.clone());
+
+    assert_eq!(dto.agent_id, r.agent_id.to_string());
+    assert_eq!(dto.name, "Architect");
+    assert_eq!(dto.node_id, r.node_id.to_string());
+    assert_eq!(dto.conversation_id.as_deref(), Some("conv-123"));
+    assert!(dto.was_running);
+    assert!(dto.resume_supported);
+}
+
+#[test]
+fn from_resumable_agent_ids_are_strings() {
+    let r = full(7, 8);
+    let dto = ResumableAgentDto::from(r.clone());
+    // The ids cross the wire as UUID strings (not raw bytes / numbers).
+    assert_eq!(dto.agent_id, Uuid::from_u128(7).to_string());
+    assert_eq!(dto.node_id, Uuid::from_u128(8).to_string());
+}
+
+// ---------------------------------------------------------------------------
+// camelCase wire shape + conversationId omission
+// ---------------------------------------------------------------------------
+
+#[test]
+fn full_dto_serialises_camelcase_with_conversation() {
+    let dto = ResumableAgentDto::from(full(1, 2));
+    let v = serde_json::to_value(&dto).unwrap();
+
+    assert_eq!(v["agentId"], Uuid::from_u128(1).to_string());
+    assert_eq!(v["name"], "Architect");
+    assert_eq!(v["nodeId"], Uuid::from_u128(2).to_string());
+    assert_eq!(v["conversationId"], "conv-123");
+    assert_eq!(v["wasRunning"], true);
+    assert_eq!(v["resumeSupported"], true);
+
+    // No snake_case leak.
+    assert!(v.get("agent_id").is_none(), "no snake_case leak: {v}");
+    assert!(v.get("node_id").is_none());
+    assert!(v.get("conversation_id").is_none());
+    assert!(v.get("was_running").is_none());
+    assert!(v.get("resume_supported").is_none());
+}
+
+#[test]
+fn minimal_dto_omits_conversation_id_when_none() {
+    let dto = ResumableAgentDto::from(minimal(3, 4));
+    let v = serde_json::to_value(&dto).unwrap();
+
+    // conversationId must be OMITTED (absent, not null) when None.
+    assert!(
+        v.get("conversationId").is_none(),
+        "None conversation ⇒ conversationId omitted, got: {v}"
+    );
+    // Required flags are still present.
+    assert_eq!(v["wasRunning"], false);
+    assert_eq!(v["resumeSupported"], false);
+    assert_eq!(v["name"], "Scratch");
+}
+
+// ---------------------------------------------------------------------------
+// Round-trip serde (Serialize → Deserialize) on the camelCase shape
+// ---------------------------------------------------------------------------
+
+/// A `Deserialize` twin matching the wire shape, used to prove the serialised
+/// JSON is exactly the camelCase contract the frontend `ResumableAgent` mirror
+/// consumes (`ResumableAgentDto` is serialise-only on the prod side).
+#[derive(serde::Deserialize)]
+#[serde(rename_all = "camelCase", deny_unknown_fields)]
+struct WireResumableAgent {
+    agent_id: String,
+    name: String,
+    node_id: String,
+    #[serde(default)]
+    conversation_id: Option<String>,
+    was_running: bool,
+    resume_supported: bool,
+}
+
+#[test]
+fn full_dto_round_trips_camelcase() {
+    let dto = ResumableAgentDto::from(full(1, 2));
+    let json = serde_json::to_string(&dto).unwrap();
+    let back: WireResumableAgent = serde_json::from_str(&json).unwrap();
+
+    assert_eq!(back.agent_id, Uuid::from_u128(1).to_string());
+    assert_eq!(back.name, "Architect");
+    assert_eq!(back.node_id, Uuid::from_u128(2).to_string());
+    assert_eq!(back.conversation_id.as_deref(), Some("conv-123"));
+    assert!(back.was_running);
+    assert!(back.resume_supported);
+}
+
+#[test]
+fn minimal_dto_round_trips_camelcase_without_conversation() {
+    let dto = ResumableAgentDto::from(minimal(3, 4));
+    let json = serde_json::to_string(&dto).unwrap();
+    // The key is absent from the JSON entirely.
+    assert!(
+        !json.contains("conversationId"),
+        "minimal ⇒ no conversationId key, got: {json}"
+    );
+    let back: WireResumableAgent = serde_json::from_str(&json).unwrap();
+    assert_eq!(back.conversation_id, None);
+    assert!(!back.was_running);
+    assert!(!back.resume_supported);
+}
+
+// ---------------------------------------------------------------------------
+// From<ListResumableAgentsOutput> for ResumableAgentListDto — list + order
+// ---------------------------------------------------------------------------
+
+#[test]
+fn from_output_preserves_list_and_order() {
+    let out = ListResumableAgentsOutput {
+        resumable: vec![full(10, 11), minimal(20, 21), full(30, 31)],
+    };
+    let dto = ResumableAgentListDto::from(out);
+
+    assert_eq!(dto.resumable.len(), 3);
+    // Order preserved.
+    assert_eq!(dto.resumable[0].agent_id, Uuid::from_u128(10).to_string());
+    assert_eq!(dto.resumable[1].agent_id, Uuid::from_u128(20).to_string());
+    assert_eq!(dto.resumable[2].agent_id, Uuid::from_u128(30).to_string());
+    // Middle entry is the minimal one (no conversation).
+    assert!(dto.resumable[1].conversation_id.is_none());
+}
+
+#[test]
+fn empty_output_serialises_empty_resumable_array() {
+    let dto = ResumableAgentListDto::from(ListResumableAgentsOutput::default());
+    let v = serde_json::to_value(&dto).unwrap();
+    assert_eq!(v["resumable"], serde_json::json!([]));
+}
+
+#[test]
+fn list_dto_serialises_camelcase_wrapper() {
+    let out = ListResumableAgentsOutput {
+        resumable: vec![full(10, 11)],
+    };
+    let dto = ResumableAgentListDto::from(out);
+    let v = serde_json::to_value(&dto).unwrap();
+
+    // Wrapper key is `resumable`; nested entries are camelCase.
+    let arr = v["resumable"].as_array().expect("resumable is an array");
+    assert_eq!(arr.len(), 1);
+    assert_eq!(arr[0]["agentId"], Uuid::from_u128(10).to_string());
+    assert_eq!(arr[0]["nodeId"], Uuid::from_u128(11).to_string());
+}