chantier: durcissement reprise headless inter-projets + persistance profils Opencode

- Implémentation reprise de session Opencode headless (conversational_recovery)
- Persistance des profils IA Opencode dans .ideai/memory avec JSON Schema
- Gestion des permissions MCP pour agents externes
- Tests QA verts : structured_launch_d3, conversation_log, tickets_missing_carnet, agents, ProfilesSettings

crates/app-tauri/src/tickets.rs

@@ -72,8 +72,18 @@ impl TicketToolProvider for AppTicketToolProvider {
                     .await
                     .map_err(ticket_error)?
                     .issue;
+                let fallback_carnet = issue.carnet.as_str().to_owned();
                 let carnet = if include_carnet {
-                    Some(read_carnet_body(&*self.read_carnet, project, issue_ref).await?)
+                    Some(
+                        read_ticket_carnet_body_best_effort(
+                            &*self.read_carnet,
+                            project,
+                            issue_ref,
+                            fallback_carnet,
+                        )
+                        .await
+                        .map_err(ticket_error)?,
+                    )
                 } else {
                     None
                 };
@@ -287,17 +297,17 @@ pub async fn ticket_read(
         .await
         .map_err(ErrorDto::from)?
         .issue;
+    let fallback_carnet = issue.carnet.as_str().to_owned();
     let carnet = if request.include_carnet.unwrap_or(false) {
         Some(
-            state
-                .read_issue_carnet
-                .execute(ReadIssueCarnetInput { project, issue_ref })
-                .await
-                .map_err(ErrorDto::from)?
-                .carnet
-                .carnet
-                .as_str()
-                .to_owned(),
+            read_ticket_carnet_body_best_effort(
+                &state.read_issue_carnet,
+                &project,
+                issue_ref,
+                fallback_carnet,
+            )
+            .await
+            .map_err(ErrorDto::from)?,
         )
     } else {
         None
@@ -680,6 +690,25 @@ async fn read_carnet_body(
         .map_err(ticket_error)
 }
 
+async fn read_ticket_carnet_body_best_effort(
+    read_carnet: &application::ReadIssueCarnet,
+    project: &Project,
+    issue_ref: IssueRef,
+    fallback_carnet: String,
+) -> Result<String, AppError> {
+    match read_carnet
+        .execute(ReadIssueCarnetInput {
+            project: project.clone(),
+            issue_ref,
+        })
+        .await
+    {
+        Ok(out) => Ok(out.carnet.carnet.as_str().to_owned()),
+        Err(AppError::NotFound(_)) => Ok(fallback_carnet),
+        Err(err) => Err(err),
+    }
+}
+
 fn ticket_error(err: AppError) -> TicketToolError {
     let message = err.to_string();
     let code = if message.contains("issue version conflict") {