FIX isolate TAP configuration and per-run state

[Roman Lutz (romanlutz)]

Description

TreeOfAttacksWithPruningAttack stored its visualization root on the reusable attack instance, so concurrent executions with different prepended conversation depths could attach first-level nodes to the wrong parent.

This change moves the visualization root into TAPAttackContext and consolidates six stable tree-search settings into a private frozen configuration object. The existing keyword-only constructor remains the compatibility layer, preserving its parameter names, defaults, validation messages, factory reflection, PAIR behavior, identifiers, and persistence/resume contracts. No public configuration API or migration is introduced.

Tests and Documentation

• Added coverage for default and custom configuration, exact validation behavior, immutability, legacy constructor compatibility, PAIR's pinned settings, and deterministic interleaved execution contexts.
• Ran 118 focused TAP/PAIR tests and 153 factory, registry, parameter-consistency, Foundry, and schema-forwarding tests.
• Ran Ruff check, Ruff format check, and focused ty check on the changed files.
• Documentation was not changed because the public API and behavior remain compatible.
• JupyText was not applicable.