Reduce bundle size

From https://github.com/hzrd149/nostrudel/pull/11

Currently we depend on nostr-tools and some other packages, which are more bloated than necessary. We might be able to replace these with more cut-down versions or implement the code ourselves.

This will get worse when we add further integrations which require their own packages such as LNC.

Review the issue description and the referenced nostrudel pull request first; no source files, tests, entry points, bundle target, or dependency list are identified here. Determine which dependencies contribute to the bundle and define a measurable size target before choosing an implementation approach. Done should include a verified bundle-size reduction without breaking the stated integrations.

Written by the indexing model from the issue text.