[AUTO] JuliaFormatter.jl run

- Add ControlFreeModel and WithControlModel type aliases for dispatch
- Implement Flow(ocp) and Flow(ocp, g, μ) for control-free problems
- Add new makeH variants passing Float64[] as control
- Add __create_hamiltonian overloads for control-free OCPs
- Add PreconditionError guards for existing Flow(ocp, u) methods
- Add comprehensive tests (17 new tests, all passing)
- Follow all project standards (SOLID, documentation, testing, exceptions)
- Support state constraints and multipliers for control-free problems
- Maintain full backward compatibility (45/45 tests passing)

Closes #173

- Remove See also: [](@ref) references
- Remove See also: [](@ref) references
- These references were causing documentation build errors
- Documentation is now clean and ready for deployment

- Bump version from 0.8.20 to 0.8.21-beta for control-free features
- Add comprehensive CHANGELOG entry for 0.8.21-beta with all control-free functionality
- Add missing 0.8.20 version entry for auto-formatter PR
- Document 17 new tests and 45 total passing tests
- Maintain changelog format standards with proper sectioning

feat: Add control-free optimal control problems support

- Add augment::Bool=false keyword to OptimalControlFlow point evaluation
- When augment=true, compute costate pv(tf) associated with variable v
- Implementation uses Flow(Hamiltonian(H_aug)) to avoid ::ctVector issues
- rhs_augmented kept as documented utility (fails with OCP Hamiltonians)
- Comprehensive test suite with 55 tests covering all cases
- Supports scalar/vector states and variables
- Proper error handling for Fixed models and trajectory calls
- Version bump to 0.8.23-beta

- Document augment=true keyword feature
- Add comprehensive changelog entry with 55 tests
- Note implementation details and fixes