- Add isPlainRecord() type guard to eliminate 'as Record<string, unknown>' casts
- Replace 'as any' with properly typed assertions in start.ts
- Remove 'null as unknown as' pattern in kernel.ts
- Add type predicates for array narrowing (item is string)
- Improve IPC message type narrowing in daemon-client.ts and ipc.ts
- Type better-sqlite3 and drizzle return values properly
No runtime behavior changes.
xingyue