feat(session-manager): add version-gated SDK read path for OpenCode beta

- Add SDK client injection via setStorageClient()

- Version-gate getMainSessions(), getAllSessions(), readSessionMessages(), readSessionTodos()

- Add comprehensive tests for SDK path (beta mode)

- Maintain backward compatibility with JSON fallback

src/features/hook-message-injector/index.ts

@@ -1,4 +1,10 @@
-export { injectHookMessage, findNearestMessageWithFields, findFirstMessageWithAgent } from "./injector"
+export {
+  injectHookMessage,
+  findNearestMessageWithFields,
+  findFirstMessageWithAgent,
+  findNearestMessageWithFieldsFromSDK,
+  findFirstMessageWithAgentFromSDK,
+} from "./injector"
 export type { StoredMessage } from "./injector"
 export type { MessageMeta, OriginalMessageContext, TextPart, ToolPermission } from "./types"
 export { MESSAGE_STORAGE } from "./constants"