feat: add autoware_lanelet2_map_merger package

[mitsudome-r]

Description

Part of autowarefoundation/autoware_core#887

Add a new autoware_lanelet2_map_merger package that merges a directory of divided Lanelet2 (.osm) map files into a single .osm file.

• New ROS 2 node autoware_lanelet2_map_merger_node with launch file, parameter YAML, and JSON schema.
• Loads every .osm file in the input directory using the projector described in map_projector_info.yaml (MGRS, LocalCartesianUTM, LocalCartesian, and TransverseMercator are supported).
• Merges the loaded maps using the same logic as lanelet2_map_loader (merge_lanelet2_maps), deduplicating points shared across maps by ID so successor/predecessor relationships are preserved, then writes the merged map with lanelet::write.
• Includes README and a gtest covering the merge behavior.

How was this PR tested?

• Built the package with colcon build --packages-select autoware_lanelet2_map_merger.
• Ran the included gtest suite (test_lanelet2_map_merger) via colcon test.
• Verified end-to-end round-trip by running autoware_lanelet2_map_divider on a sample lanelet2_map.osm and then running this merger on its output, confirming the reconstructed map matches the original.

Notes for reviewers

None.

Effects on system behavior

None.

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[Copilot]

Pull request overview

Adds a new ROS 2 “map tool” package that merges a directory of divided Lanelet2 .osm files back into a single .osm, using a projector described by map_projector_info.yaml and preserving shared-point IDs to keep topology consistent.

Changes:

• Introduces autoware_lanelet2_map_merger library + component node to discover, load, merge, and write Lanelet2 maps.
• Adds launch/config + parameter JSON schema and README documentation.
• Adds a gtest that exercises merge/dedup and reload behavior.

Reviewed changes

Copilot reviewed 12 out of 12 changed files in this pull request and generated 7 comments.

Show a summary per file

File	Description
map/autoware_lanelet2_map_merger/src/lanelet2_map_merger.cpp	Core discovery/load/merge/write implementation.
map/autoware_lanelet2_map_merger/src/lanelet2_map_merger.hpp	Merger class interface and state (loaded map lifetime).
map/autoware_lanelet2_map_merger/src/lanelet2_map_merger_node.cpp	One-shot ROS 2 node wrapper that runs the merger from parameters.
map/autoware_lanelet2_map_merger/src/lanelet2_map_merger_node.hpp	Node class declaration.
map/autoware_lanelet2_map_merger/src/local_projector.hpp	Minimal projector used for LOCAL projector-type handling.
map/autoware_lanelet2_map_merger/test/test_lanelet2_map_merger.cpp	Unit tests for merge/dedup + reload + non-crash behavior.
map/autoware_lanelet2_map_merger/CMakeLists.txt	Build/test targets and component registration.
map/autoware_lanelet2_map_merger/package.xml	Package metadata and dependencies.
map/autoware_lanelet2_map_merger/launch/lanelet2_map_merger.launch.xml	Launch entrypoint wiring parameters.
map/autoware_lanelet2_map_merger/config/lanelet2_map_merger.param.yaml	Default parameter file using launch substitutions.
map/autoware_lanelet2_map_merger/schema/lanelet2_map_merger.schema.json	Parameter schema for documentation/validation.
map/autoware_lanelet2_map_merger/README.md	Usage and behavior documentation.

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[codecov]

Codecov Report

❌ Patch coverage is 24.74227% with 73 lines in your changes missing coverage. Please review.
✅ Project coverage is 7.08%. Comparing base (700c544) to head (8e10f11).
⚠️ Report is 2 commits behind head on main.

Files with missing lines	Patch %	Lines
...re_lanelet2_map_merger/src/lanelet2_map_merger.cpp	20.27%	15 Missing and 44 partials ⚠️
...nelet2_map_merger/src/lanelet2_map_merger_node.cpp	0.00%	12 Missing and 1 partial ⚠️
...toware_lanelet2_map_merger/src/local_projector.hpp	83.33%	0 Missing and 1 partial ⚠️

Additional details and impacted files

@@           Coverage Diff            @@
##            main    #410      +/-   ##
========================================
+ Coverage   7.02%   7.08%   +0.05%     
========================================
  Files        497     501       +4     
  Lines      32735   32818      +83     
  Branches    3736    3793      +57     
========================================
+ Hits        2301    2325      +24     
- Misses     29079   29100      +21     
- Partials    1355    1393      +38     

Flag	Coverage Δ		*Carryforward flag
differential-jazzy	24.74% <24.74%> (?)
total	3.33% <ø> (+<0.01%)	⬆️	Carriedforward from 700c544
total-humble	4.93% <ø> (+<0.01%)	⬆️	Carriedforward from 700c544
total-jazzy	4.77% <ø> (+<0.01%)	⬆️	Carriedforward from 700c544

*This pull request uses carry forward flags. Click here to find out more.

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