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/infrastructure/tests/conversation_log.rs

@@ -1294,6 +1294,64 @@ async fn provider_is_isolated_per_conversation() {
     );
 }
 
+#[tokio::test]
+async fn provider_is_isolated_per_project_root_with_same_conversation_and_provider() {
+    let project_a = TempDir::new();
+    let project_b = TempDir::new();
+    let store_a = FsProviderSessionStore::new(&project_a.project_path());
+    let store_b = FsProviderSessionStore::new(&project_b.project_path());
+    let c = conv_id(77);
+
+    store_a.set(c, "opencode", "engine-a").await.unwrap();
+    store_b.set(c, "opencode", "engine-b").await.unwrap();
+
+    assert_eq!(
+        store_a.get(c, "opencode").await.unwrap(),
+        Some("engine-a".to_owned())
+    );
+    assert_eq!(
+        store_b.get(c, "opencode").await.unwrap(),
+        Some("engine-b".to_owned())
+    );
+    assert!(
+        !std::fs::read_to_string(project_a.providers_path(c))
+            .unwrap()
+            .contains("engine-b"),
+        "project A providers.json must not contain project B's engine id"
+    );
+    assert!(
+        !std::fs::read_to_string(project_b.providers_path(c))
+            .unwrap()
+            .contains("engine-a"),
+        "project B providers.json must not contain project A's engine id"
+    );
+}
+
+#[tokio::test]
+async fn provider_unresolved_project_root_fails_closed() {
+    let root = ProjectPath::new(format!(
+        "{}/missing-{}",
+        std::env::temp_dir().to_string_lossy(),
+        Uuid::new_v4()
+    ))
+    .unwrap();
+    let store = FsProviderSessionStore::new(&root);
+    let c = conv_id(78);
+
+    assert_eq!(
+        store.get(c, "opencode").await.unwrap(),
+        None,
+        "unresolved root cannot produce a resumable id"
+    );
+    assert!(
+        matches!(
+            store.set(c, "opencode", "engine").await,
+            Err(StoreError::Io(_))
+        ),
+        "unresolved root must not write outside a canonical project root"
+    );
+}
+
 // ===========================================================================
 // LS6 — rotation (ConversationArchive) + pagination humaine, I/O réelle.
 // Réutilise le scaffolding L2 (TempDir absolu, constructeurs déterministes).