SearchTree renamed SearchGraph

[robfitzgerald]

ever since we introduced the LabelModel, search is no longer guaranteed to produce a tree. this PR renames SearchTree to SearchGraph. the description describes it as a directed acyclic graph (DAG). this covers the wider definition of what we build in cases where a node may have multiple parents.

this is mostly to align naming conventions with the upcoming journal paper.

[Copilot]

Pull request overview

Renames the core search structure from SearchTree to SearchGraph to reflect that the search space is no longer guaranteed to be a strict tree after introducing LabelModel (aligning terminology with upcoming publication language).

Changes:

• Replaced SearchTree/SearchTreeNode/SearchTreeError with SearchGraph/SearchGraphNode/SearchGraphError across core search APIs and dependent crates.
• Updated traversal/cost/termination/model interfaces and implementations to accept &SearchGraph.
• Updated output plugins and docs to consume/emit “graph” results (while some legacy “tree” naming remains in outputs).

Reviewed changes

Copilot reviewed 47 out of 47 changed files in this pull request and generated 6 comments.

Show a summary per file

File	Description
rust/routee-compass/src/plugin/output/default/traversal/traversal_output_format.rs	Accept SearchGraph for traversal output generation
rust/routee-compass/src/plugin/output/default/traversal/traversal_ops.rs	Traversal output helpers updated to use SearchGraph
rust/routee-compass/src/plugin/output/default/traversal/plugin.rs	Traversal plugin reads result.graphs
rust/routee-compass/src/plugin/output/default/summary/plugin.rs	Summary plugin counts edges from result.graphs
rust/routee-compass/src/plugin/output/default/eval/ops.rs	Removed unused test helper in eval ops tests
rust/routee-compass/src/app/search/search_app.rs	Maps algorithm trees into app-level graphs
rust/routee-compass/src/app/search/search_app_result.rs	Renamed result field to graphs: Vec<SearchGraph>
rust/routee-compass/src/app/compass/compass_app_ops.rs	Updated empty result construction to graphs
rust/routee-compass-powertrain/src/model/phev_energy_model.rs	Traversal model signature now uses SearchGraph
rust/routee-compass-powertrain/src/model/ice_energy_model.rs	Traversal model signature now uses SearchGraph
rust/routee-compass-powertrain/src/model/charging/simple_charging_model.rs	Updated signatures/tests to SearchGraph
rust/routee-compass-powertrain/src/model/bev_energy_model.rs	Traversal model signature now uses SearchGraph
rust/routee-compass-core/src/util/geo/polygonal_rtree.rs	Local variable rename (unrelated to search graph)
rust/routee-compass-core/src/testing/mock/traversal_model.rs	Mock traversal model updated to SearchGraph
rust/routee-compass-core/src/model/traversal/traversal_model.rs	Trait updated: tree param -> graph type/name
rust/routee-compass-core/src/model/traversal/default/turn_delays/turn_delay_traversal_model.rs	Uses SearchGraph for prior-edge lookup
rust/routee-compass-core/src/model/traversal/default/time/time_traversal_model.rs	Updated traversal hooks to SearchGraph
rust/routee-compass-core/src/model/traversal/default/temperature/temperature_traversal_model.rs	Updated traversal hooks to SearchGraph
rust/routee-compass-core/src/model/traversal/default/speed/speed_traversal_model.rs	Updated traversal hooks/tests to SearchGraph
rust/routee-compass-core/src/model/traversal/default/grade/grade_traversal_model.rs	Updated traversal hooks to SearchGraph
rust/routee-compass-core/src/model/traversal/default/elevation/elevation_traversal_model.rs	Updated traversal hooks to SearchGraph
rust/routee-compass-core/src/model/traversal/default/distance/distance_traversal_model.rs	Updated traversal hooks to SearchGraph
rust/routee-compass-core/src/model/traversal/default/custom/custom_traversal_model.rs	Updated traversal hooks to SearchGraph
rust/routee-compass-core/src/model/traversal/default/combined/combined_traversal_model.rs	Propagates SearchGraph through combined model
rust/routee-compass-core/src/model/traversal/default/combined/combined_ops.rs	Test types updated to SearchGraph
rust/routee-compass-core/src/model/termination/model.rs	Termination checks now accept SearchGraph
rust/routee-compass-core/src/model/label/label_model.rs	Docstrings updated to refer to SearchGraph
rust/routee-compass-core/src/model/label/label_enum.rs	Docstrings updated to refer to SearchGraph
rust/routee-compass-core/src/model/cost/network/network_cost_rate.rs	Cost rate hook signature uses SearchGraph
rust/routee-compass-core/src/model/cost/cost_model.rs	Traversal cost computation uses SearchGraph
rust/routee-compass-core/src/algorithm/search/search_result.rs	SearchResult stores SearchGraph (field still tree)
rust/routee-compass-core/src/algorithm/search/search_pruning.rs	Pruning renamed to prune_graph + new error type
rust/routee-compass-core/src/algorithm/search/search_instance.rs	Internal solution container now SearchGraph
rust/routee-compass-core/src/algorithm/search/search_graph.rs	New SearchGraph type (renamed from tree)
rust/routee-compass-core/src/algorithm/search/search_graph_node.rs	Node type renamed to SearchGraphNode
rust/routee-compass-core/src/algorithm/search/search_error.rs	Error variant wraps SearchGraphError
rust/routee-compass-core/src/algorithm/search/search_algorithm.rs	Updated comment reference to SearchGraph
rust/routee-compass-core/src/algorithm/search/search_algorithm_result.rs	Algorithm result uses Vec<SearchGraph> (field still trees)
rust/routee-compass-core/src/algorithm/search/mod.rs	Module exports switched from tree to graph modules
rust/routee-compass-core/src/algorithm/search/ksp/svp.rs	Uses SearchGraphNode in KSP logic
rust/routee-compass-core/src/algorithm/search/edge_traversal.rs	Edge traversal creation now accepts &SearchGraph
rust/routee-compass-core/src/algorithm/search/a_star/frontier_instance.rs	Frontier logic now uses &SearchGraph
rust/routee-compass-core/src/algorithm/search/a_star/a_star_algorithm.rs	A* now builds/returns SearchGraph
rust/routee-compass-core/src/algorithm/map_matching/model/lcss/lcss_ops.rs	Map matching error variant renamed to graph
rust/routee-compass-core/src/algorithm/map_matching/map_matching_error.rs	Error type updated to SearchGraphError
rust/routee-compass-codegen/src/generator/traversal.rs	Codegen template imports SearchGraph
docs/config.md	Updated wording removing “tree results” phrasing

Comments suppressed due to low confidence (3)

rust/routee-compass-core/src/algorithm/search/search_graph.rs:15

• The type is documented as a DAG, but insert does not enforce acyclicity (it can create cycles, and backtracking only detects cycles at runtime). Either relax the doc comment to “directed graph” / “intended to be acyclic” or add cycle-prevention checks during insertion.
  rust/routee-compass/src/plugin/output/default/traversal/traversal_ops.rs:33
• This output helper is still named create_tree_geojson (and emits error text “tree GeoJSON”) but now operates on a SearchGraph. To avoid confusion, consider renaming these helpers/messages to *_graph_* (or otherwise clarifying that this is legacy naming for graph output).
  rust/routee-compass/src/plugin/output/default/summary/plugin.rs:35
• tree_edges is now computed from result.graphs, and the JSON key is still tree_size_count. If this is truly a graph now, consider renaming the variable/key to avoid confusing downstream consumers; if the key must remain for compatibility, add an explicit comment and at least rename the local variable to graph_edges for clarity.

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[robfitzgerald]

@nreinicke regarding multiedge vs optimal edge: the default behavior is to plot all edges of a search graph. i'm just going to leave it there for this PR and if we want to, we can revisit traversal_ops::create_graph_multilinestring and pick the top-scoring Label for each VertexId when grabbing all edges.