Update Abstract Base Classes with COCO/BBOB Requirements

[Anselmoo]

Problem

Abstract base classes (AbstractOptimizer and AbstractMultiObjectiveOptimizer) lack COCO/BBOB compliance documentation, providing no centralized guidance for 120+ concrete implementations.

Solution

Update both abstract base classes with COCO/BBOB requirements to establish centralized foundation before updating individual optimizers.

Implementation

File 1: opt/abstract_optimizer.py

Add to module docstring:

"""Abstract base class for single-objective optimizers.

**COCO/BBOB Compliance Requirements:**
All concrete optimizer implementations inheriting from this class must provide:
- Algorithm metadata (name, version, authors, year, class)
- BBOB benchmark settings (search space, dimensions, runs, seeds)
- Hyperparameter documentation with BBOB-recommended values
- Reproducibility requirements (seed logging, parameter tracking)
- Performance characteristics on BBOB function classes
- Complexity analysis (time/space, function evaluations)

See `.github/prompts/optimizer-docs-template.md` for complete template.
"""

Add to AbstractOptimizer.__init__ docstring:

• Document seed parameter as REQUIRED for BBOB
• Document track_history for COCO postprocessing
• Specify BBOB standard values (search space [-5,5], dimensions, budget 10^4*dim)

File 2: opt/multi_objective/abstract_multi_objective.py

Add multi-objective BBOB adaptations:

• Pareto front reproducibility
• Multi-objective performance indicators (Hypervolume, IGD, Spread)
• Seed logging requirements

Acceptance Criteria

• opt/abstract_optimizer.py updated with COCO/BBOB requirements
• opt/multi_objective/abstract_multi_objective.py updated with multi-objective adaptations
• Both files pass uv run ruff check
• Validation test passes:

uv run python -c "
from opt.abstract_optimizer import AbstractOptimizer
from opt.multi_objective.abstract_multi_objective import AbstractMultiObjectiveOptimizer
import inspect
doc_single = inspect.getdoc(AbstractOptimizer)
assert 'COCO/BBOB' in doc_single
assert 'seed' in doc_single.lower()
doc_multi = inspect.getdoc(AbstractMultiObjectiveOptimizer)
assert 'multi-objective' in doc_multi.lower()
assert 'seed' in doc_multi.lower()
print('✅ Both base classes BBOB compliant')
"

Complexity

Medium - Requires understanding BBOB standards and abstract class patterns

Dependencies

Depends on: #1 (template must exist first)
Blocks: #3-#14 (establishes centralized foundation)