Adapt to CTModels v0.7.x and integrate CTSolvers

[ocots]

Context

This issue tracks the adaptation of OptimalControl to work with CTModels v0.7.x as part of the breaking change migration.

Related to: control-toolbox/CTModels.jl#247

Objectives

1. Adapt OptimalControl code to work with CTModels v0.7.x API
2. Integrate CTSolvers v0.2.x as a new dependency
3. Update code to use CTSolvers functionality
4. Widen compat constraints to support both CTModels 0.6 and 0.7

Version Changes

• Before: OptimalControl v1.1.8-beta
• After: OptimalControl v2.0.0-beta (major version bump)

Major Changes

1. Ecosystem Restructuring

• Integration of new CTSolvers package
• New solver architecture
• Separation of concerns (solvers moved to dedicated package)

2. Breaking Dependency Updates

• CTModels v0.7.x (breaking changes)
• CTDirect v0.18.x (major version bump)
• New dependency: CTSolvers v0.2.x

3. API Changes

• Adaptation to new CTModels API
• Integration of CTSolvers functionality
• Potential breaking changes in user-facing API

Project.toml Changes

# Before
version = "1.1.8-beta"

[compat]
CTDirect = "0.17"
CTFlows = "0.8"
CTModels = "0.6"
CTParser = "0.8"
CTBase = "0.17"

# After
version = "2.0.0-beta"

[compat]
CTDirect = "0.17, 0.18"
CTFlows = "0.8"
CTModels = "0.6, 0.7"
CTParser = "0.8"
CTSolvers = "0.2"  # NEW
CTBase = "0.17"

Tasks

• Adapt code to CTModels v0.7.x API
• Integrate CTSolvers as dependency
• Update code to use CTSolvers functionality
• Update Project.toml with new version and compat
• Run tests with CTModels v0.7.0-beta and CTSolvers v0.2.0-beta
• Verify all tests pass
• Register v2.0.0-beta in ct-registry
• Create GitHub tag v2.0.0-beta

Migration Status

Phase 1: CTFlows v0.8.11-beta ✅
Phase 2: CTModels v0.7.0-beta ✅
Phase 3: CTDirect v0.18.0-beta ✅
Phase 3.5: CTSolvers v0.2.0-beta ✅
Phase 4: OptimalControl v2.0.0-beta 🔄 (this issue)
Phase 5: Stabilization ⏳

References

• Migration plan: action-plan.md
• CTModels issue: Breaking change migration: CTModels 0.6.10-beta → 0.7.0-beta CTModels.jl#247
• Methodology: breaking-change-rules.md

[ocots]

GitHub Issue Comment - OptimalControl v2.0.0 Migration Roadmap

Post this comment to the OptimalControl issue to explain the detailed migration plan.

---

🎯 Migration Roadmap - OptimalControl v2.0.0

This migration will follow a phased beta approach with systematic validation of all sub-packages in the control-toolbox ecosystem.

Phase 4: OptimalControl Adaptation (3 Steps)

Step 1: Initial Integration → v2.0.0-beta.1

Objective: Minimal viable integration with CTSolvers

Tasks:

• Integrate solve_api.jl from CTSolvers (source)
• Integrate associated tests (source)
• Temporarily comment out other tests
• Release v2.0.0-beta.1

Step 2: Export Macro Improvement

Objective: Simplify import/export management

Current pattern (repetitive):

import CTBase: foo, bar, baz
export foo, bar  # baz not exported

New pattern (with macro):

@reexport_from CTBase [foo, bar, baz] exclude=[baz]

Benefits: Reduces duplication, makes exclusions explicit, easier to maintain

Step 3: Complete Integration → v2.0.0-beta.2

Objective: Full test suite passing

Tasks:

• Re-enable all tests
• Fix any compatibility issues
• Release v2.0.0-beta.2

---

Phase 5: Systematic Sub-Package Validation

Strategy: Bottom-up validation through dependency tree

Each sub-package will undergo systematic improvements using CTBase extensions:

1. Coverage Improvement (using CoveragePostprocessing.jl)
2. Documentation Enhancement (using DocumenterReference.jl)
3. Test Execution Modernization (using TestRunner.jl)

Validation Order

CTBase → CTModels, CTParser → CTFlows, CTSolvers → CTDirect → OptimalControl

Package-Specific Tasks

CTModels:

• Clarify interfaces (especially options)
• Add modeler options if needed
• Add Makie extension

CTFlows:

• Finalize code restructuring
• Introduce new features

CTParser:

• Review and determine improvements

CTSolvers:

• Add solver options

CTDirect:

• Update tests to use CTSolvers
• Rewrite Collocation discretizer
• Choose definitive discretizer name

OptimalControl:

• Final integration and v2.0.0 stable release

---

Timeline Estimate

Phase	Duration
4.1 (beta.1)	1-2 days
4.2 (export macro)	2-3 days
4.3 (beta.2)	1-2 days
5 (sub-packages)	2-3 weeks
Total	~4 weeks

---

Tools & Extensions

All from CTBase:

• CoveragePostprocessing.jl
• DocumenterReference.jl
• TestRunner.jl

---

Success Criteria

• ✅ All tests passing
• ✅ >90% code coverage for all packages
• ✅ Complete API documentation
• ✅ All sub-packages at validated beta versions

---

Related: control-toolbox/CTModels.jl#247

See detailed roadmap for complete information.