Motivation

• Avoid building an intermediate untyped JSON tree to reduce memory pressure and parsing overhead.
• Keep OSM data typed during parsing to simplify downstream processing and error handling.
• Reduce expensive cloning of way/node data when assembling relations.
• Free large temporary maps earlier so memory can be reused during generation.

Description

• Parse Overpass/file responses with streaming deserialization using serde_json::Deserializer::from_reader(...) directly into OsmData in src/retrieve_data.rs and return OsmData instead of Value.
• Make OsmData a public typed struct (including remark) and update parse_osm_data to accept OsmData in src/osm_parser.rs.
• Replace ways_map storage with HashMap<u64, Arc<ProcessedWay>> and change ProcessedMember to hold Arc<ProcessedWay> to avoid cloning way node vectors repeatedly.
• Drop nodes_map and ways_map after processing relations to release memory earlier and update call sites (src/test_utilities.rs) to use the new typed fetch return.

Testing

• Ran cargo fmt to apply formatting changes and ensure code style is consistent, which completed successfully.
• No automated unit/integration tests were executed as part of this change set.

Codex Task