fix(orchestrator,plugins): contact cross-project corrélé + découvrabilité assignation plugin par agent — #284 (backend: registre des demandes actives clé projet/agent appelant + correlationId, refus corrélation vide/dupliquée, cancel routé après correspondance exacte sans redirection vers une autre cible, appelant projeté Waiting→Done dans le live-state de son propre projet avec correlationId exposé par idea_workstate_read, gardes RAII réconcilient l'abandon du futur, tools ask/cancel WriteAction deny-by-default dont le refus indique où activer la permission; frontend: action Attribuer aux agents depuis Settings projet > Plugins ouvrant le panneau Agents flottant/ancré/détaché, section Capabilities de plugins — {agent} explicitant attribution skills et tools MCP des plugins activés; QA verte: orchestrator_service 79/79, mcp_server 40/40, domain live_state 15/15, correlated_update_is_preserved_in_the_lean_projection 1/1, frontend ProjectPluginSettings 3 tests, npm run build frontend, cargo fmt --check, git diff --check; AppImage IdeA_0.3.0_amd64.AppImage rebuildée workflow build-appimage, validation live cross-project restant après remplacement/relance manuels; réserves: registre corrélation en mémoire non persisté, surface web unsupported, catalogue dynamique tools MCP = réserve #282)

crates/infrastructure/src/orchestrator/mcp/server.rs

@@ -443,9 +443,14 @@ impl McpServer {
         } else {
             &self.requester
         };
+        let guidance = if matches!(name, "idea_project_ask_agent" | "idea_project_cancel_agent") {
+            "; enable this cross-project action in the requester's project MCP tool permissions"
+        } else {
+            ""
+        };
         Err(JsonRpcError::new(
             error_codes::INVALID_PARAMS,
-            format!("MCP tool `{name}` is not permitted for requester {requester}"),
+            format!("MCP tool `{name}` is not permitted for requester {requester}{guidance}"),
         ))
     }
 

crates/infrastructure/src/orchestrator/mcp/tools.rs

@@ -228,7 +228,7 @@ pub fn catalogue() -> Vec<ToolDef> {
         },
         ToolDef {
             name: "idea_project_ask_agent",
-            description: "Ask a cross-project contactable agent by projectId and agentId and wait for its final answer.",
+            description: "Ask a cross-project contactable agent by projectId and agentId and wait for its final answer. Requires explicit permission in the requester's project MCP tool settings.",
             input_schema: json!({
                 "type": "object",
                 "properties": {
@@ -243,7 +243,7 @@ pub fn catalogue() -> Vec<ToolDef> {
         },
         ToolDef {
             name: "idea_project_cancel_agent",
-            description: "Cancel/stop a cross-project contactable agent by projectId, agentId and correlationId.",
+            description: "Cancel an active cross-project request by the same projectId, agentId and correlationId used for the ask. Requires explicit permission in the requester's project MCP tool settings.",
             input_schema: json!({
                 "type": "object",
                 "properties": {

crates/infrastructure/tests/mcp_server.rs

@@ -928,6 +928,60 @@ async fn requester_with_durable_store_but_no_override_sees_read_only_tools() {
     assert!(!names.contains(&"idea_template_delete"));
     assert!(!names.contains(&"idea_plugin_install_from_directory"));
     assert!(!names.contains(&"idea_plugin_reload"));
+    assert!(!names.contains(&"idea_project_ask_agent"));
+    assert!(!names.contains(&"idea_project_cancel_agent"));
+}
+
+#[tokio::test]
+async fn cross_project_actions_are_advertised_only_when_allowed_and_denial_is_actionable() {
+    let (service, _s) = build_service(FakeContexts::new());
+    let agent = AgentId::from_uuid(Uuid::from_u128(284));
+    let allowed = server_with_mcp_permissions(
+        Arc::clone(&service),
+        allow_doc(
+            agent,
+            &["idea_project_ask_agent", "idea_project_cancel_agent"],
+        ),
+    )
+    .for_requester(agent.to_string());
+
+    let listed = allowed
+        .handle_raw(
+            &serde_json::to_vec(&json!({
+                "jsonrpc": "2.0", "id": 284, "method": "tools/list"
+            }))
+            .unwrap(),
+        )
+        .await
+        .expect("tools/list reply");
+    let listed_result = listed.result.unwrap();
+    let names: Vec<&str> = listed_result["tools"]
+        .as_array()
+        .unwrap()
+        .iter()
+        .map(|tool| tool["name"].as_str().unwrap())
+        .collect();
+    assert!(names.contains(&"idea_project_ask_agent"));
+    assert!(names.contains(&"idea_project_cancel_agent"));
+
+    let denied = server_with_mcp_permissions(service, ProjectMcpToolPermissions::default())
+        .for_requester(agent.to_string());
+    let response = denied
+        .handle_raw(&tools_call(
+            285,
+            "idea_project_ask_agent",
+            json!({
+                "projectId": Uuid::from_u128(2),
+                "agentId": Uuid::from_u128(3),
+                "correlationId": "corr-denied",
+                "task": "work"
+            }),
+        ))
+        .await
+        .expect("denied call reply");
+    let error = response.error.expect("permission error");
+    assert!(error.message.contains("not permitted"));
+    assert!(error.message.contains("project MCP tool permissions"));
 }
 
 // ---------------------------------------------------------------------------