feat(tickets): ajoute les pièces jointes sur tickets (#108)

Stockage flat côté ticket + métadonnées d'attachments, lecture exposée côté
backend/MCP, et UI minimale de liste/ajout dans TicketDetail. Traverse le
domaine (Issue, ports), l'application (usecases + assistant de ticket), les
adaptateurs infra/MCP (issues store, orchestrateur), les DTO backend/web-
server/app-tauri, et le frontend (domain/ports/adapters/hooks/UI).

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

crates/infrastructure/tests/issue_store.rs

@@ -2,9 +2,9 @@ use std::path::PathBuf;
 use std::str::FromStr;
 
 use domain::{
-    AgentId, AgentIssueRef, AgentIssueRole, Issue, IssueActor, IssueId, IssueListFilter,
-    IssueNumberAllocator, IssuePriority, IssueRef, IssueStatus, IssueStore, IssueStoreError,
-    MarkdownDoc, ProjectPath, SprintId,
+    AgentId, AgentIssueRef, AgentIssueRole, Issue, IssueActor, IssueAttachmentId, IssueId,
+    IssueListFilter, IssueNumberAllocator, IssuePriority, IssueRef, IssueStatus, IssueStore,
+    IssueStoreError, LocalPath, MarkdownDoc, ProjectPath, SprintId,
 };
 use infrastructure::{FsIssueNumberAllocator, FsIssueStore};
 use uuid::Uuid;
@@ -402,6 +402,66 @@ async fn issue_store_persists_and_filters_sprint_membership() {
     assert_eq!(rows[0].sprint, Some(sprint_id));
 }
 
+#[tokio::test]
+async fn issue_store_adds_reads_and_marks_attachment_summarized() {
+    let tmp = TempDir::new();
+    let root = tmp.root();
+    let store = FsIssueStore::new();
+    let issue = issue(&root, 7, "Attachment ticket");
+    store.create(&root, &issue).await.unwrap();
+    let source = tmp.child("source-note.txt");
+    std::fs::write(&source, "attachment payload").unwrap();
+    let attachment_id = IssueAttachmentId::new("att_1".to_owned()).unwrap();
+
+    let updated = store
+        .add_attachment_from_path(
+            &root,
+            issue.reference(),
+            &LocalPath::new(source.to_string_lossy().to_string()),
+            attachment_id.clone(),
+            "source-note.txt".to_owned(),
+            "text/plain".to_owned(),
+            IssueActor::User,
+            2_000,
+            issue.version,
+        )
+        .await
+        .unwrap();
+
+    assert_eq!(updated.attachments.len(), 1);
+    assert_eq!(updated.attachments[0].filename, "source-note.txt");
+    assert_eq!(updated.attachments[0].mime, "text/plain");
+    assert_eq!(updated.attachments[0].size_bytes, 18);
+    assert!(!updated.attachments[0].summarized_in_carnet);
+    assert!(tmp
+        .child(".ideai/tickets/7/attachments/att_1-source-note.txt")
+        .exists());
+
+    let content = store
+        .read_attachment(&root, issue.reference(), &attachment_id)
+        .await
+        .unwrap();
+    assert_eq!(content.attachment.id, attachment_id);
+    assert_eq!(content.bytes, b"attachment payload");
+
+    let summarized = store
+        .mark_attachment_summarized(
+            &root,
+            issue.reference(),
+            &attachment_id,
+            IssueActor::System,
+            3_000,
+            updated.version,
+        )
+        .await
+        .unwrap();
+
+    let attachment = &summarized.attachments[0];
+    assert!(attachment.summarized_in_carnet);
+    assert_eq!(attachment.summarized_by, Some(IssueActor::System));
+    assert_eq!(attachment.summarized_at, Some(3_000));
+}
+
 #[tokio::test]
 async fn issue_store_delete_removes_files_and_index_entry() {
     let tmp = TempDir::new();