Add rich show methods for all problem components

[aarontrowbridge]

Summary

• Add informative Base.show methods to all objectives (QuadraticRegularizer, LinearRegularizer, KnotPointObjective, MinimumTimeObjective, GlobalObjective, GlobalKnotPointObjective, CompositeObjective, NullObjective), constraints (EqualityConstraint, BoundsConstraint, TimeConsistencyConstraint, L1SlackConstraint, SymmetryConstraint, AllEqualConstraint, TotalConstraint, NonlinearKnotPointConstraint, NonlinearGlobalConstraint, NonlinearGlobalKnotPointConstraint), and integrators (BilinearIntegrator, DerivativeIntegrator, TimeDependentBilinearIntegrator)
• Replace the minimal DirectTrajOptProblem display with a hierarchical view showing trajectory details, weighted objective breakdown, dynamics integrators, and constraint summary grouped by type
• Export show_problem_details helper for use by downstream packages (e.g. Piccolo.jl's QuantumControlProblem)

Example output

DirectTrajOptProblem
  Trajectory
    Timesteps: 51
    Duration:  10.0
    Knot dim:  14
    Variables: Ũ⃗ (8), u (2), du (2), ddu (2), Δt (1), t (1)
    Controls:  u, du, ddu, Δt
  Objective (4 terms)
       100.0 * KnotPointObjective on [:Ũ⃗] at t = [51]
        0.01 * QuadraticRegularizer on :u (R = [0.01, 0.01], all)
        0.01 * QuadraticRegularizer on :du (R = [0.01, 0.01], all)
        0.01 * QuadraticRegularizer on :ddu (R = [0.01, 0.01], all)
  Dynamics (3 integrators)
    BilinearIntegrator: :Ũ⃗ = exp(Δt G(:u)) :Ũ⃗  (dim = 8)
    DerivativeIntegrator: :u += Δt * :du  (dim = 2)
    DerivativeIntegrator: :du += Δt * :ddu  (dim = 2)
  Constraints (8 total: 2 equality, 4 bounds, 1 time consistency, 1 other)
    EqualityConstraint: "initial value of Ũ⃗"
    BoundsConstraint: "bounds on u"
    BoundsConstraint: "bounds on ddu"
    BoundsConstraint: "bounds on Δt"
    TimeConsistencyConstraint: t_{k+1} = t_k + Δt_k
    ...

Test plan

• Run existing test suite to verify no regressions
• Create a problem in REPL and verify display output

🤖 Generated with Claude Code

[Copilot]

Pull request overview

This PR enhances the display output for trajectory optimization problems by adding informative Base.show methods to all problem components. The changes transform the minimal problem display into a hierarchical, readable summary that shows trajectory details, weighted objectives, dynamics integrators, and grouped constraints.

Changes:

• Added Base.show methods for all objectives (8 types), constraints (10 types), and integrators (3 types)
• Replaced minimal DirectTrajOptProblem display with comprehensive hierarchical view
• Exported show_problem_details helper for downstream package reuse (e.g., Piccolo.jl)

Reviewed changes

Copilot reviewed 19 out of 19 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
src/problems.jl	Added show_problem_details function with hierarchical display of trajectory, objectives, dynamics, and constraints; exported for downstream use
src/objectives/regularizers.jl	Added show methods for QuadraticRegularizer and LinearRegularizer with R values and time coverage
src/objectives/minimum_time_objective.jl	Added show method for MinimumTimeObjective displaying D parameter
src/objectives/knot_point_objectives.jl	Added show method for KnotPointObjective displaying variables and time points
src/objectives/global_objectives.jl	Added show methods for GlobalObjective and GlobalKnotPointObjective with global variable info
src/objectives/_objectives.jl	Enhanced CompositeObjective show method to display all terms with weights; added NullObjective show method
src/integrators/bilinear_integrator.jl	Added show method displaying integration formula and dimension
src/integrators/derivative_integrator.jl	Added show method displaying derivative integration formula
src/integrators/time_dependent_bilinear_integrator.jl	Added show method with time-dependent formula and spline order
src/constraints/nonlinear/knot_point_constraint.jl	Added show method displaying variables, equality/inequality type, and times
src/constraints/nonlinear/global_knot_point_constraint.jl	Added show method for global knot point constraints
src/constraints/nonlinear/global_constraint.jl	Added show method for global constraints
src/constraints/linear/total_constraint.jl	Added show method displaying constraint label
src/constraints/linear/time_consistency_constraint.jl	Added show method with consistency formula
src/constraints/linear/symmetry_constraint.jl	Added show method displaying symmetry type and components
src/constraints/linear/l1_slack_constraint.jl	Added show method with L1 constraint formula
src/constraints/linear/equality_constraint.jl	Added show method displaying constraint label
src/constraints/linear/bounds_constraint.jl	Added show method displaying constraint label
src/constraints/linear/all_equal_constraint.jl	Added show method displaying constraint label

Comments suppressed due to low confidence (2)

src/objectives/regularizers.jl:69

• The logic for determining "all" times may be misleading when times is a contiguous range starting from 1 but doesn't cover all trajectory timesteps. For example, if times = [1, 2, 3] on a trajectory with 100 timesteps, this would display "all" instead of "3 times". Consider checking if times equals the full range 1:traj.N, but this requires storing a reference to the trajectory size or revising the display logic to be more conservative (e.g., only show "all" if times appears to be the default 1:n range and add a comment noting this limitation).

    times_str = (!isempty(reg.times) && first(reg.times) == 1 && last(reg.times) == n) ? "all" : "$n times"

src/objectives/regularizers.jl:226

• Same issue as in QuadraticRegularizer: the logic for determining "all" times may be misleading when times is a contiguous range starting from 1 but doesn't cover all trajectory timesteps. Consider using the same fix applied to QuadraticRegularizer for consistency.

    times_str = (!isempty(reg.times) && first(reg.times) == 1 && last(reg.times) == n) ? "all" : "$n times"

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