// this_file: crates/vexy-vsvg-plugin-sdk/src/plugins/cleanup_ids/collector.rs
//! ID collection logic for the cleanupIds plugin.
//!
//! This module would contain ID collection helper functions if they were
//! factored out from the main module. Currently, all collection logic
//! lives in `mod.rs` within the `CleanupIdsVisitor`.
//!
//! ## Collection strategy
//!
//! The plugin makes two passes:
//! 1. **Collection pass**: Walk the tree, record all IDs and where they're referenced
//! 2. **Application pass**: Remove unused IDs, rename used IDs, update all references
//!
//! This two-pass approach ensures we know the full reference graph before making changes.