FIX Handle attack parameter construction failures

[Roman Lutz (romanlutz)]

Description

Parameter construction for multi-objective attacks previously used fail-fast gathering, even when return_partial_on_failure=True. A simulated-conversation build could already perform model calls and persist memory state before a sibling failed, after which no successfully built objective executed and Scenario retry regenerated that work.

This change makes parameter construction follow the executor's existing failure contract:

• Partial mode executes successfully built objectives and reports build and execution failures in original input order.
• Strict mode settles parameter builds, suppresses outer attack execution when any build fails, and raises the first input-ordered build error.
• Cancellation and other fatal BaseException values continue to propagate.
• Completed result indices retain their original seed-group positions so Scenario retry skips persisted successes and avoids duplicate materialization.

Tests and Documentation

Added deterministic event-controlled tests for out-of-order build failures, mixed build/execution failures, strict suppression, cancellation propagation, original input-index alignment, and real Strategy-to-AtomicAttack-to-Scenario-to-CentralMemory retry linkage.

Validation:

• Focused contract tests: 14 passed.
• Executor, parameter, simulated-conversation, Scenario retry/partial-result, and attack-result memory tests: 214 passed.
• Ruff check and format check passed for all changed files.
• ty passed for all changed files.

Documentation was not changed because this fixes the existing return_partial_on_failure contract without adding a new public API. JupyText was not applicable.