Fix #289: Add ShortestWeightConstrainedPath model

[zazabap]

Summary

• Add ShortestWeightConstrainedPath satisfaction problem model (bicriteria s-t path with length and weight bounds)
• Register in CLI dispatch, aliases, and create command
• Unit tests with brute-force solver verification
• Paper documentation

Fixes #289

[codecov]

Codecov Report

❌ Patch coverage is 98.43260% with 5 lines in your changes missing coverage. Please review.
✅ Project coverage is 97.60%. Comparing base (cb32085) to head (537166b).
⚠️ Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
...c/models/graph/shortest_weight_constrained_path.rs	97.42%	5 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff            @@
##             main     #632    +/-   ##
========================================
  Coverage   97.59%   97.60%            
========================================
  Files         387      389     +2     
  Lines       48159    48478   +319     
========================================
+ Hits        47002    47316   +314     
- Misses       1157     1162     +5     

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[GiggleLiu]

Implementation Summary

Changes

• Added src/models/graph/shortest_weight_constrained_path.rs implementing the ShortestWeightConstrainedPath<G, N> satisfaction model with binary edge-selection encoding, path validation, canonical example-db registration, and declare_variants! complexity "2^num_edges".
• Registered and re-exported the model in src/models/graph/mod.rs, src/models/mod.rs, and src/lib.rs.
• Added model coverage in src/unit_tests/models/graph/shortest_weight_constrained_path.rs, src/unit_tests/trait_consistency.rs, and tests/suites/integration.rs.
• Added CLI create support in problemreductions-cli/src/cli.rs and problemreductions-cli/src/commands/create.rs, plus regression coverage in problemreductions-cli/tests/cli_tests.rs.
• Added paper/docs entries in docs/paper/reductions.typ and docs/paper/references.bib, then regenerated src/example_db/fixtures/examples.json, docs/src/reductions/problem_schemas.json, and docs/src/reductions/reduction_graph.json.
• src/unit_tests/example_db.rs and src/unit_tests/export.rs only changed due cargo fmt after verification.

Deviations from Plan

• The resumed PR branch was stale, so I merged origin/main into it before implementation to pick up the current pipeline scripts and repo structure.
• The original review packet only saw the previously committed plan-file diff on the resumed branch, so I completed the review pass against the current working-tree patch and fixed the findings directly.
• During review I renamed the numeric generic from W to N to match the issue spec and maintainer feedback, and I added negative CLI regression tests for the new error paths.

Open Questions

• None.

[Copilot]

Pull request overview

Adds a new graph satisfaction model, ShortestWeightConstrainedPath, to the problemreductions catalog, integrating it into the CLI and documentation pipeline alongside tests and canonical examples.

Changes:

• Introduces ShortestWeightConstrainedPath model with schema registration, variants, evaluation logic, and canonical example-db spec.
• Wires the model into public exports (models, prelude), CLI pred create flag parsing, and CLI test coverage.
• Updates example-db fixtures and generated docs JSON (problem schemas + reduction graph) plus paper documentation/references.

Reviewed changes

Copilot reviewed 17 out of 17 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
tests/suites/integration.rs	Adds integration coverage ensuring the brute-force solver can find a satisfying config.
src/unit_tests/trait_consistency.rs	Extends trait-consistency checks to include the new model.
src/unit_tests/models/graph/shortest_weight_constrained_path.rs	Adds unit tests for construction, accessors, evaluation, brute-force enumeration, and serde roundtrip.
src/unit_tests/export.rs	Minor formatting adjustment in export-related test.
src/unit_tests/example_db.rs	Refactors formatting/labeling in fixture verification assertions.
src/models/mod.rs	Re-exports the new graph model at the models module level.
src/models/graph/shortest_weight_constrained_path.rs	Implements the model + schema entry + canonical example + variant declaration.
src/models/graph/mod.rs	Registers module, re-export, and canonical example spec aggregation.
src/lib.rs	Exposes the new model via the prelude.
src/example_db/fixtures/examples.json	Adds canonical example fixture entry for the new model.
problemreductions-cli/tests/cli_tests.rs	Adds CLI tests for pred create ShortestWeightConstrainedPath and error cases.
problemreductions-cli/src/commands/create.rs	Implements pred create construction path and edge-length parsing helper.
problemreductions-cli/src/cli.rs	Adds new CLI flags (--edge-lengths, bounds, source/target) and help text.
docs/src/reductions/reduction_graph.json	Updates generated reduction graph catalog to include the new node/variant.
docs/src/reductions/problem_schemas.json	Updates generated schema catalog to include the new problem’s fields.
docs/paper/references.bib	Adds citations relevant to constrained shortest path.
docs/paper/reductions.typ	Adds paper section/example/figure for the new model.

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[GiggleLiu]

Review Pipeline Report

Check	Result
Copilot comments	0 actionable
Issue/human comments	4 checked, 2 fixed
Structural review	17/17 passed
CI	green
Agentic test	passed
Needs human decision	none
Board	Review pool -> Under review -> Final review

Remaining issues for final review

• None.

🤖 Generated by review-pipeline