[ENGINEERING] Add API documentation for public modules

[developerfred]

Problem

While lib.rs has documentation, many public modules lack doc comments.

Current State

• lib.rs - Good documentation with /// comments
• src/error.rs - Good module documentation
• Most other modules - Missing //! module-level docs

Recommendation

Add doc comments to:

• src/package/mod.rs
• src/events/mod.rs
• src/logging/mod.rs
• src/deployment/mod.rs
• src/compiler/ modules
• src/runtime/ modules

Documentation Guidelines

//! Package management for Bend-PVM
//!
//! This module provides semantic versioning, dependency resolution,
//! and package registry functionality.

pub use package::{Package, Version, PackageRegistry};

Priority

Medium - Affects API discoverability

Labels

• engineering
• documentation
• help-wanted

[developerfred]

Documentation added in PR #84