chore(chat): instrumentation session CustomAgentChatView pour diagnostic #149

Ajoute des points de traçage ciblés sur le cycle de vie de session
CustomAgentChatView/LayoutGrid pour isoler la cause du fallback
silencieux CLI custom avant tentative de fix.

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

frontend/src/features/agents/CustomAgentChatView.tsx

@@ -40,6 +40,19 @@ function describe(e: unknown): string {
   return String(e);
 }
 
+function instrumentationError(e: unknown): Record<string, unknown> {
+  if (e && typeof e === "object") {
+    const err = e as GatewayError & { name?: string };
+    return {
+      code: err.code,
+      message: err.message,
+      name: err.name,
+      raw: e,
+    };
+  }
+  return { message: String(e), raw: e };
+}
+
 function isNotFound(e: unknown): boolean {
   return Boolean(e && typeof e === "object" && (e as GatewayError).code === "NOT_FOUND");
 }
@@ -127,6 +140,7 @@ export function CustomAgentChatView({
   const sessionRef = useRef<string | null>(sessionId);
   sessionRef.current = currentSession;
   const mountedRef = useRef(false);
+  const openOrAttachCountRef = useRef(0);
   const onSessionIdRef = useRef(onSessionId);
   onSessionIdRef.current = onSessionId;
   const onConversationIdRef = useRef(onConversationId);
@@ -156,7 +170,28 @@ export function CustomAgentChatView({
   const reattachStructuredSession = useCallback(
     async (sid: string, options: { applyScrollback?: boolean } = {}) => {
       if (!agent.reattachAgentChat) throw new Error("Structured reattach unavailable");
-      const reattached = await agent.reattachAgentChat(sid, receive);
+      console.debug("[ticket149] reattachStructuredSession:start", {
+        timestamp: new Date().toISOString(),
+        sessionId: sid,
+        options,
+      });
+      let reattached: Awaited<ReturnType<NonNullable<typeof agent.reattachAgentChat>>>;
+      try {
+        reattached = await agent.reattachAgentChat(sid, receive);
+      } catch (e) {
+        console.error("[ticket149] reattachStructuredSession:error", {
+          timestamp: new Date().toISOString(),
+          sessionId: sid,
+          error: instrumentationError(e),
+        });
+        throw e;
+      }
+      console.debug("[ticket149] reattachStructuredSession:success", {
+        timestamp: new Date().toISOString(),
+        requestedSessionId: sid,
+        returnedSessionId: reattached.sessionId,
+        scrollbackCount: reattached.scrollback.length,
+      });
       if (!mountedRef.current) return reattached.sessionId;
       setCurrentSession(reattached.sessionId);
       if (options.applyScrollback) {
@@ -170,14 +205,47 @@ export function CustomAgentChatView({
   const recoverStructuredSession = useCallback(
     async (options: { applyScrollback?: boolean; retryAttachNotFound?: boolean } = {}) => {
       if (!agent.launchAgentChat) throw new Error("Structured launch unavailable");
+      console.debug("[ticket149] recoverStructuredSession:start", {
+        timestamp: new Date().toISOString(),
+        currentSession: sessionRef.current,
+        conversationId,
+        options,
+      });
       let retryAttachNotFound = Boolean(options.retryAttachNotFound);
       for (;;) {
-        const launched = await agent.launchAgentChat(projectId, agentId, {
+        const launchRequest = {
           cwd,
           rows: 24,
           cols: 80,
           conversationId: conversationId ?? undefined,
           nodeId,
+        };
+        console.debug("[ticket149] recoverStructuredSession:launchAgentChat:start", {
+          timestamp: new Date().toISOString(),
+          projectId,
+          agentId,
+          request: launchRequest,
+          options,
+          retryAttachNotFound,
+        });
+        let launched: Awaited<ReturnType<NonNullable<typeof agent.launchAgentChat>>>;
+        try {
+          launched = await agent.launchAgentChat(projectId, agentId, launchRequest);
+        } catch (e) {
+          console.error("[ticket149] recoverStructuredSession:launchAgentChat:error", {
+            timestamp: new Date().toISOString(),
+            projectId,
+            agentId,
+            request: launchRequest,
+            error: instrumentationError(e),
+          });
+          throw e;
+        }
+        console.debug("[ticket149] recoverStructuredSession:launchAgentChat:success", {
+          timestamp: new Date().toISOString(),
+          projectId,
+          agentId,
+          launched,
         });
         if (!mountedRef.current) return launched.sessionId;
         setCurrentSession(launched.sessionId);
@@ -186,9 +254,15 @@ export function CustomAgentChatView({
           onConversationIdRef.current(launched.assignedConversationId);
         }
         try {
-          return await reattachStructuredSession(launched.sessionId, {
+          const recoveredSessionId = await reattachStructuredSession(launched.sessionId, {
             applyScrollback: options.applyScrollback,
           });
+          console.debug("[ticket149] recoverStructuredSession:success", {
+            timestamp: new Date().toISOString(),
+            launchedSessionId: launched.sessionId,
+            recoveredSessionId,
+          });
+          return recoveredSessionId;
         } catch (e) {
           if (isNotFound(e) && retryAttachNotFound) {
             retryAttachNotFound = false;
@@ -198,6 +272,11 @@ export function CustomAgentChatView({
             }
             continue;
           }
+          console.error("[ticket149] recoverStructuredSession:reattach:error", {
+            timestamp: new Date().toISOString(),
+            launchedSessionId: launched.sessionId,
+            error: instrumentationError(e),
+          });
           throw e;
         }
       }
@@ -223,6 +302,13 @@ export function CustomAgentChatView({
     let cancelled = false;
 
     async function openOrAttach() {
+      const execution = openOrAttachCountRef.current + 1;
+      openOrAttachCountRef.current = execution;
+      console.debug("[ticket149] openOrAttach:start", {
+        timestamp: new Date().toISOString(),
+        execution,
+        sessionId,
+      });
       setOpening(true);
       setError(null);
       try {
@@ -230,6 +316,11 @@ export function CustomAgentChatView({
           try {
             await reattachStructuredSession(sessionId, { applyScrollback: true });
             if (cancelled) return;
+            console.debug("[ticket149] openOrAttach:reattach-existing:success", {
+              timestamp: new Date().toISOString(),
+              execution,
+              sessionId,
+            });
             return;
           } catch (e) {
             // The backend contract for `reattach_agent_chat` (NOT_FOUND) is that
@@ -240,6 +331,12 @@ export function CustomAgentChatView({
               setCurrentSession(null);
               onSessionIdRef.current(null);
             }
+            console.debug("[ticket149] openOrAttach:reattach-existing:not-found", {
+              timestamp: new Date().toISOString(),
+              execution,
+              sessionId,
+              error: instrumentationError(e),
+            });
           }
         }
         await recoverStructuredSession({
@@ -247,7 +344,18 @@ export function CustomAgentChatView({
           retryAttachNotFound: true,
         });
         if (cancelled) return;
+        console.debug("[ticket149] openOrAttach:recover:success", {
+          timestamp: new Date().toISOString(),
+          execution,
+          receivedSessionId: sessionId,
+        });
       } catch (e) {
+        console.error("[ticket149] openOrAttach:error", {
+          timestamp: new Date().toISOString(),
+          execution,
+          sessionId,
+          error: instrumentationError(e),
+        });
         if (!cancelled) setError(describe(e));
       } finally {
         if (!cancelled) setOpening(false);

frontend/src/features/layout/LayoutGrid.tsx

@@ -624,8 +624,7 @@ function LeafView({
         legitChange?.agentId === pinnedAgent.id &&
         legitChange.profileId === pinnedAgent.profileId,
     );
-    if (
+    const fallbackInput = {
-      shouldFallbackCustomCliMode({
       agentsLoaded,
       profilesLoaded,
       cellMode,
@@ -635,8 +634,14 @@ function LeafView({
       effectiveCustomCliAvailable,
       hasTrustedCustomCli: Boolean(trustedCustomCli),
       hasLegitProfileChange: hasLegitDowngrade,
-      })
+    };
-    ) {
+    const shouldFallback = shouldFallbackCustomCliMode(fallbackInput);
+    console.debug("[ticket149] shouldFallbackCustomCliMode", {
+      timestamp: new Date().toISOString(),
+      input: fallbackInput,
+      result: shouldFallback,
+    });
+    if (shouldFallback) {
       setTrustedCustomCli(null);
       setCellMode("tui");
     }
@@ -693,6 +698,22 @@ function LeafView({
     else setCellMode(target);
   }
 
+  async function setSessionWithInstrumentation(
+    site: "custom" | "plain" | "plain-background-attach" | "mode-switch",
+    nextSession: string | null,
+  ): Promise<void> {
+    console.debug("[ticket149] vm.setSession", {
+      timestamp: new Date().toISOString(),
+      nodeId: id,
+      site,
+      previousSession: session,
+      nextSession,
+      cellMode,
+      agentId,
+    });
+    await vm.setSession(id, nextSession);
+  }
+
   async function stopCurrentSessionForSwitch(): Promise<void> {
     if (!session) return;
     if (agentId && agentGateway?.stopLiveAgent) {
@@ -708,7 +729,7 @@ function LeafView({
     } else {
       await terminal?.closeTerminal(session);
     }
-    await vm.setSession(id, null);
+    await setSessionWithInstrumentation("mode-switch", null);
     refreshLive();
   }
 
@@ -863,7 +884,7 @@ function LeafView({
     if (background?.sessionId && agentGateway!.attachLiveAgent) {
       const attached = await agentGateway!.attachLiveAgent(projectId, agentId!, id);
       const sessionId = attached.sessionId ?? background.sessionId;
-      void vm.setSession(id, sessionId);
+      void setSessionWithInstrumentation("plain-background-attach", sessionId);
       const result = await agentGateway!.reattach(sessionId, onData);
       refreshLive();
       return result.handle;
@@ -1299,7 +1320,7 @@ function LeafView({
             nodeId={id}
             sessionId={session}
             conversationId={conversationId}
-            onSessionId={(sid) => void vm.setSession(id, sid)}
+            onSessionId={(sid) => void setSessionWithInstrumentation("custom", sid)}
             onConversationId={(cid) => void vm.setCellConversation(id, cid)}
           />
         ) : (
@@ -1309,7 +1330,7 @@ function LeafView({
             open={terminalOpener}
             reattach={reattachOpener}
             sessionId={session}
-            onSessionId={(sid) => void vm.setSession(id, sid)}
+            onSessionId={(sid) => void setSessionWithInstrumentation("plain", sid)}
             agentMode={agentId != null}
             portal={agentId != null ? portal : undefined}
             refitSignal={refitSignal}