Fix #497: [Model] SequencingToMinimizeWeightedCompletionTime

[GiggleLiu]

Summary

• add the SequencingToMinimizeWeightedCompletionTime model with Lehmer-code schedules, canonical examples, registry wiring, and paper coverage
• add the SequencingToMinimizeWeightedCompletionTime -> ILP<i32> reduction with example-db wiring and closed-loop/solver tests
• extend pred create with --lengths, --weights, and --precedence-pairs, plus a CLI regression test

Verification

• make test
• make clippy
• make paper
• cargo test -p problemreductions-cli test_create_sequencing_to_minimize_weighted_completion_time
• cargo clippy --all-targets --all-features -- -D warnings is blocked locally because scip-sys cannot find a SCIP installation in this environment

Fixes #497

[codecov]

Codecov Report

❌ Patch coverage is 99.17526% with 4 lines in your changes missing coverage. Please review.
✅ Project coverage is 97.52%. Comparing base (2228c61) to head (fa005f4).
⚠️ Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
...sequencing_to_minimize_weighted_completion_time.rs	97.14%	4 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #669      +/-   ##
==========================================
+ Coverage   97.50%   97.52%   +0.01%     
==========================================
  Files         363      367       +4     
  Lines       45954    46439     +485     
==========================================
+ Hits        44806    45288     +482     
- Misses       1148     1151       +3     

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[Copilot]

Pull request overview

Adds the SequencingToMinimizeWeightedCompletionTime scheduling model (Lehmer-code schedule representation) and integrates it across the library, docs, example DB, and CLI; also introduces a reduction from this model to ILP<i32> with solver/closed-loop tests.

Changes:

• Introduce the SequencingToMinimizeWeightedCompletionTime model + schema/variants + canonical examples.
• Add SequencingToMinimizeWeightedCompletionTime -> ILP<i32> reduction with example-db wiring and unit tests.
• Extend pred create to construct this model via --lengths, --weights, and optional --precedence-pairs, plus a CLI regression test.

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
src/models/misc/sequencing_to_minimize_weighted_completion_time.rs	New model implementation (Lehmer code configs, metric evaluation, schema + variants + examples).
src/unit_tests/models/misc/sequencing_to_minimize_weighted_completion_time.rs	Model unit tests (evaluation correctness, invalid configs, serialization, brute force optimum).
src/rules/sequencingtominimizeweightedcompletiontime_ilp.rs	New ILP reduction (big-M disjunction with pairwise order vars) + example-db hook + tests module.
src/unit_tests/rules/sequencingtominimizeweightedcompletiontime_ilp.rs	Reduction shape, solution extraction, closed-loop, infeasibility, and brute-force agreement tests.
src/rules/mod.rs	Registers the new ILP rule module + canonical rule examples wiring.
src/models/misc/mod.rs	Registers the new misc model module and exports it + example-db specs wiring.
src/models/mod.rs	Re-exports the new model at the crate models root.
src/lib.rs	Exposes the new model in the public prelude.
src/unit_tests/trait_consistency.rs	Adds trait consistency + direction tests for the new model.
src/example_db/fixtures/examples.json	Adds canonical example instance + rule example; regenerates fixtures (also updates some existing solution samples).
docs/src/reductions/problem_schemas.json	Adds generated schema entry for the new model.
docs/src/reductions/reduction_graph.json	Adds generated node/edge for the new model and its ILP reduction.
docs/paper/references.bib	Adds Lawler (1978) + Smith (1956) references for paper coverage.
docs/paper/reductions.typ	Adds paper definition + example figure + ILP reduction writeup.
problemreductions-cli/src/cli.rs	Adds --lengths flag and updates “Flags by problem type” for the new model.
problemreductions-cli/src/commands/create.rs	Implements pred create SequencingToMinimizeWeightedCompletionTime ... parsing and instance construction.
problemreductions-cli/tests/cli_tests.rs	Adds CLI regression test for pred create of the new model.

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[GiggleLiu]

Review Pipeline Report

Check	Result
Copilot comments	2 fixed
Issue/human comments	1 checked, 0 fixed
Structural review	passed after fixing 2 findings
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

[GiggleLiu]

Review Pipeline Update

Check	Result
Copilot comments	2 fixed
Issue/human comments	1 checked, 0 fixed
Structural review	passed after fixing 4 findings
CI	no checks attached to current head 04f4de20
Agentic test	passed
Needs human decision	none
Board	Review pool → Under review

Remaining issues for final review

• GitHub Actions has not attached any checks to the current PR head 04f4de20 even after a no-op retrigger commit. Local verification is green (make test, make clippy, make paper), but the PR should remain in Under review until CI appears or is manually retriggered.

🤖 Generated by review-pipeline