chore: add interrupted tool result recovery hook to web-security

[GangGreenTemperTatum]

Summary

• add a capability-level hook for web-security that recovers when the model emits [Response interrupted by a tool call result.]
• remember the last tool outcome and feed it back to the agent with a bounded retry budget
• fix the web-security test suite so bbscope imports from the current repo layout and async marks only apply to async tests

Validation

• python3 -m pytest capabilities/web-security/tests -q
• pre-commit run --files capabilities/web-security/capability.yaml capabilities/web-security/hooks/interrupted_tool_result.py capabilities/web-security/tests/test_interrupted_tool_result_hook.py capabilities/web-security/tests/test_bbscope.py capabilities/web-security/tests/test_credence.py