Fix inconsistent default approval policy and make schema fields backward-compatible

- Unify DEFAULT_APPROVAL_POLICY to 'on-request' in ProviderCommandReactor.ts
  to match ProviderRuntimeIngestion.ts (was incorrectly 'never')
- Make approvalPolicy and sandboxMode optional with decoding defaults in
  OrchestrationSession and ThreadTurnStartRequestedPayload schemas so old
  events in the event store can be replayed without failing validation
- Add fallback defaults at consumer sites for TypeScript type narrowing

Author: cursoragent

apps/server/src/orchestration/Layers/ProjectionPipeline.ts

@@ -473,8 +473,8 @@ const makeOrchestrationProjectionPipeline = Effect.gen(function* () {
         providerName: event.payload.session.providerName,
         providerSessionId: event.payload.session.providerSessionId,
         providerThreadId: event.payload.session.providerThreadId,
-        approvalPolicy: event.payload.session.approvalPolicy,
-        sandboxMode: event.payload.session.sandboxMode,
+        approvalPolicy: event.payload.session.approvalPolicy ?? "on-request",
+        sandboxMode: event.payload.session.sandboxMode ?? "workspace-write",
         activeTurnId: event.payload.session.activeTurnId,
         lastError: event.payload.session.lastError,
         updatedAt: event.payload.session.updatedAt,

apps/server/src/orchestration/Layers/ProviderCommandReactor.ts

@@ -64,7 +64,7 @@ const serverCommandId = (tag: string): CommandId =>
 
 const HANDLED_TURN_START_KEY_MAX = 10_000;
 const HANDLED_TURN_START_KEY_TTL = Duration.minutes(30);
-const DEFAULT_APPROVAL_POLICY: ProviderApprovalPolicy = "never";
+const DEFAULT_APPROVAL_POLICY: ProviderApprovalPolicy = "on-request";
 const DEFAULT_SANDBOX_MODE: ProviderSandboxMode = "workspace-write";
 
 const make = Effect.gen(function* () {
@@ -279,8 +279,8 @@ const make = Effect.gen(function* () {
       ...(message.attachments !== undefined ? { attachments: message.attachments } : {}),
       ...(event.payload.model !== undefined ? { model: event.payload.model } : {}),
       ...(event.payload.effort !== undefined ? { effort: event.payload.effort } : {}),
-      approvalPolicy: event.payload.approvalPolicy,
-      sandboxMode: event.payload.sandboxMode,
+      approvalPolicy: event.payload.approvalPolicy ?? DEFAULT_APPROVAL_POLICY,
+      sandboxMode: event.payload.sandboxMode ?? DEFAULT_SANDBOX_MODE,
       createdAt: event.payload.createdAt,
     });
   });

packages/contracts/src/orchestration.ts

@@ -142,8 +142,12 @@ export const OrchestrationSession = Schema.Struct({
   providerName: Schema.NullOr(TrimmedNonEmptyString),
   providerSessionId: Schema.NullOr(ProviderSessionId),
   providerThreadId: Schema.NullOr(ProviderThreadId),
-  approvalPolicy: ProviderApprovalPolicy,
-  sandboxMode: ProviderSandboxMode,
+  approvalPolicy: Schema.optional(ProviderApprovalPolicy).pipe(
+    Schema.withDecodingDefault(() => "on-request" as ProviderApprovalPolicy),
+  ),
+  sandboxMode: Schema.optional(ProviderSandboxMode).pipe(
+    Schema.withDecodingDefault(() => "workspace-write" as ProviderSandboxMode),
+  ),
   activeTurnId: Schema.NullOr(TurnId),
   lastError: Schema.NullOr(TrimmedNonEmptyString),
   updatedAt: IsoDateTime,
@@ -500,8 +504,12 @@ export const ThreadTurnStartRequestedPayload = Schema.Struct({
   model: Schema.optional(TrimmedNonEmptyString),
   effort: Schema.optional(TrimmedNonEmptyString),
   assistantDeliveryMode: Schema.optional(AssistantDeliveryMode),
-  approvalPolicy: ProviderApprovalPolicy,
-  sandboxMode: ProviderSandboxMode,
+  approvalPolicy: Schema.optional(ProviderApprovalPolicy).pipe(
+    Schema.withDecodingDefault(() => "on-request" as ProviderApprovalPolicy),
+  ),
+  sandboxMode: Schema.optional(ProviderSandboxMode).pipe(
+    Schema.withDecodingDefault(() => "workspace-write" as ProviderSandboxMode),
+  ),
   createdAt: IsoDateTime,
 });