core: simplify Session.Info schema to empty struct for flexible event handling

This change removes the predefined fields from Session.Info to allow more
dynamic event-driven session data. Instead of fixed schema fields, session
information will be populated through the event system, enabling better
support for evolving session states without schema migrations.

The empty struct serves as a base that can be extended through the event
model, making it easier to add new session attributes without modifying
core schema definitions.

Author: thdxr

packages/opencode/src/v2/session.ts

@@ -17,22 +17,7 @@ export type Delivery = Schema.Schema.Type<typeof Delivery>
 
 export const DefaultDelivery = "immediate" satisfies Delivery
 
-export const Info = Schema.Struct({
-  id: SessionID,
-  slug: Schema.String,
-  projectID: ProjectID,
-  workspaceID: optionalOmitUndefined(WorkspaceID),
-  directory: Schema.String,
-  path: optionalOmitUndefined(Schema.String),
-  parentID: optionalOmitUndefined(SessionID),
-  summary: optionalOmitUndefined(Summary),
-  share: optionalOmitUndefined(Share),
-  title: Schema.String,
-  version: Schema.String,
-  time: Time,
-  permission: optionalOmitUndefined(Permission.Ruleset),
-  revert: optionalOmitUndefined(Revert),
-}).annotate({ identifier: "Session" })
+export const Info = Schema.Struct({}).annotate({ identifier: "Session" })
 
 export interface Interface {
   readonly list: (input: {