fix: set workspace-scoped runtime callback token on wake so replies persist

The message reporter and snapshot callbacks use the workspace-scoped
runtime.CallbackToken (workspaceCallbackToken), which has NO node-scoped
fallback. A freshly-woken container never runs create-workspace, so that
token was unset — the reporter hit "no auth token" and chat replies were
silently discarded (restored sessions accepted a prompt but never answered).

The DO now signs a workspace-scoped callback token and passes it on the
restore request; the vm-agent persists it via upsertWorkspaceRuntime before
resolving the snapshot callback token. Combined with the node-scoped
CALLBACK_TOKEN, this matches the normal launch (node token for node
callbacks + workspace token for message/snapshot callbacks).

Diagnosed from staging Worker logs: workspace_auth.rejected_node_scoped_token
on /session-snapshot/restore and reporter "no auth token".

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: raphaeltm

apps/api/src/durable-objects/vm-agent-container.ts

@@ -5,7 +5,7 @@ import { drizzle } from 'drizzle-orm/d1';
 import * as schema from '../db/schema';
 import type { Env } from '../env';
 import { log } from '../lib/logger';
-import { signNodeCallbackToken, signNodeManagementToken } from '../services/jwt';
+import { signCallbackToken, signNodeCallbackToken, signNodeManagementToken } from '../services/jwt';
 
 export const DEFAULT_CF_CONTAINER_SLEEP_AFTER = '1h';
 export const DEFAULT_CF_CONTAINER_ACTIVE_WORK_MAX_MS = 2 * 60 * 60 * 1000;
@@ -354,6 +354,12 @@ export class VmAgentContainer extends Container<Env> {
     const callbackToken = await signNodeCallbackToken(config.nodeId, this.env);
     await this.launch(config, { nodeCallbackToken: callbackToken });
 
+    // The fresh container never ran create-workspace, so its workspace-scoped
+    // runtime.CallbackToken is unset. The message reporter and snapshot
+    // callbacks require it (they do NOT fall back to the node-scoped token), so
+    // pass it on the restore request; without it, restored sessions accept a
+    // prompt but silently discard the agent's reply ("no auth token").
+    const workspaceCallbackToken = await signCallbackToken(config.workspaceId, this.env);
     const { token } = await signNodeManagementToken(workspace.userId, config.nodeId, config.workspaceId, this.env);
     const restoreUrl = new URL(`http://localhost:${config.vmAgentPort}/workspaces/${config.workspaceId}/agent-sessions/${agentSession.id}/restore`);
     const restoreResponse = await this.containerFetch(
@@ -369,6 +375,7 @@ export class VmAgentContainer extends Container<Env> {
           chatSessionId: workspace.chatSessionId,
           runtime: 'cf-container',
           agentType: agentSession.agentType,
+          workspaceCallbackToken,
         }),
       }),
       config.vmAgentPort

packages/vm-agent/internal/server/session_snapshot.go

@@ -120,9 +120,10 @@ func (s *Server) sessionSnapshotHandlerInput(w http.ResponseWriter, r *http.Requ
 		return nil, false
 	}
 	var body struct {
-		ChatSessionID string `json:"chatSessionId"`
-		Runtime       string `json:"runtime"`
-		AgentType     string `json:"agentType"`
+		ChatSessionID          string `json:"chatSessionId"`
+		Runtime                string `json:"runtime"`
+		AgentType              string `json:"agentType"`
+		WorkspaceCallbackToken string `json:"workspaceCallbackToken"`
 	}
 	if err := json.NewDecoder(r.Body).Decode(&body); err != nil {
 		writeError(w, http.StatusBadRequest, "invalid request body")
@@ -133,6 +134,14 @@ func (s *Server) sessionSnapshotHandlerInput(w http.ResponseWriter, r *http.Requ
 		writeError(w, http.StatusBadRequest, "chatSessionId is required")
 		return nil, false
 	}
+	// A freshly-woken container never ran create-workspace, so its
+	// runtime.CallbackToken (the workspace-scoped token used by the message
+	// reporter and the snapshot callbacks) is unset. Persist the token the
+	// control plane provides on the restore request so chat replies and
+	// snapshot callbacks can authenticate after a wake.
+	if wsToken := strings.TrimSpace(body.WorkspaceCallbackToken); wsToken != "" {
+		s.upsertWorkspaceRuntime(workspaceID, "", "", "", wsToken)
+	}
 	runtime, ok := s.getWorkspaceRuntime(workspaceID)
 	if !ok {
 		writeError(w, http.StatusNotFound, "workspace not found")