Update tsconfig: bundler resolution & path mappings

Switch moduleResolution to "bundler" in base and package tsconfigs and consolidate path aliases for monorepo packages. Remove several package-level baseUrl entries and update package paths to reference ../../packages/* (add explicit napcat-common/src and napcat-image-size/src mappings). Also add a rootDir override for napcat-core. These changes unify module resolution and path aliases so TypeScript and bundlers resolve workspace packages consistently.