feat(chat): persistance bornee du brouillon custom chat par projet/layout (#182)

crates/app-tauri/tests/dto_chat.rs

@@ -7,9 +7,10 @@
 //!   `cellKind` and PTY paths keep `"pty"`.
 
 use app_tauri_lib::dto::{
-    CellKind, ChatAttachmentDto, ChatAttachmentInputDto, ImportChatAttachmentsRequestDto,
-    ImportChatAttachmentsResponseDto, ReattachChatDto, ReplyChunk, ReplyProgressDto,
-    ReplyProgressKindDto, ReplyProgressSourceDto, ReplyProgressStageDto, TerminalSessionDto,
+    CellKind, ChatAttachmentDto, ChatAttachmentInputDto, ChatDraftScopeRequestDto,
+    ImportChatAttachmentsRequestDto, ImportChatAttachmentsResponseDto, ReadChatDraftResponseDto,
+    ReattachChatDto, ReplyChunk, ReplyProgressDto, ReplyProgressKindDto, ReplyProgressSourceDto,
+    ReplyProgressStageDto, SaveChatDraftRequestDto, TerminalSessionDto,
 };
 use application::{LaunchAgentOutput, StructuredSessionDescriptor};
 use domain::project::ProjectPath;
@@ -154,6 +155,50 @@ fn reply_chunk_rejects_snake_case_tag() {
 // Chat attachments — structured input + durable metadata, camelCase
 // ---------------------------------------------------------------------------
 
+#[test]
+fn chat_draft_scope_request_deserialises_camel_case() {
+    let dto: ChatDraftScopeRequestDto = serde_json::from_value(json!({
+        "projectId": Uuid::from_u128(1).to_string(),
+        "layoutId": Uuid::from_u128(2).to_string(),
+        "nodeId": Uuid::from_u128(3).to_string()
+    }))
+    .unwrap();
+
+    assert_eq!(dto.project_id, Uuid::from_u128(1).to_string());
+    assert_eq!(dto.layout_id, Uuid::from_u128(2).to_string());
+    assert_eq!(dto.node_id, Uuid::from_u128(3).to_string());
+}
+
+#[test]
+fn save_chat_draft_request_deserialises_text_only_camel_case() {
+    let dto: SaveChatDraftRequestDto = serde_json::from_value(json!({
+        "projectId": Uuid::from_u128(1).to_string(),
+        "layoutId": Uuid::from_u128(2).to_string(),
+        "nodeId": Uuid::from_u128(3).to_string(),
+        "text": "draft text"
+    }))
+    .unwrap();
+
+    assert_eq!(dto.text, "draft text");
+}
+
+#[test]
+fn read_chat_draft_response_serialises_camel_case() {
+    let dto = ReadChatDraftResponseDto {
+        text: Some("draft text".to_owned()),
+        updated_at_ms: Some(42),
+    };
+    let v = serde_json::to_value(dto).unwrap();
+
+    assert_eq!(v["text"], "draft text");
+    assert_eq!(v["updatedAtMs"], 42);
+    assert!(v.get("updated_at_ms").is_none(), "no snake_case leak");
+    assert!(
+        v.get("attachments").is_none(),
+        "drafts never persist attachments"
+    );
+}
+
 #[test]
 fn chat_attachment_input_dto_deserialises_camel_case() {
     let dto: ChatAttachmentInputDto = serde_json::from_value(json!({