fix(refusal_classifier): quote self-referential annotation to fix import NameError

[Anai-Guo]

Problem

agentic_security/refusal_classifier/hybrid_classifier.py raises NameError at import time, which breaks the entire HybridRefusalClassifier module (and any test or code that imports it).

The add_detector method is defined inside class HybridRefusalClassifier with a return annotation that refers to the class itself:

class HybridRefusalClassifier:
    def add_detector(
        self,
        detector: RefusalDetector,
        weight: float = 1.0,
        name: str | None = None,
    ) -> HybridRefusalClassifier:   # <-- evaluated eagerly during class-body execution

The module does not use from __future__ import annotations, so this return annotation is evaluated eagerly while the class body is still executing — at which point the name HybridRefusalClassifier is not yet bound. Importing the module fails:

$ python -c "import agentic_security.refusal_classifier.hybrid_classifier"
NameError: name 'HybridRefusalClassifier' is not defined

Because tests/unit/refusal_classifier/test_hybrid_classifier.py imports the module at the top level, that whole test file currently fails to collect.

The module-level factory create_hybrid_classifier(...) -> HybridRefusalClassifier is fine — it runs after the class is defined; only the in-class self-reference is affected.

Fix

Quote the self-referential annotation so it becomes a forward reference (standard PEP 484 pattern), matching how self-references are normally written without from __future__ import annotations:

    ) -> "HybridRefusalClassifier":

One-line change, no behavior change.

Verification

Before: import agentic_security.refusal_classifier.hybrid_classifier → NameError.
After: the module imports cleanly and HybridRefusalClassifier() instantiates, so tests/unit/refusal_classifier/test_hybrid_classifier.py can be collected again.

🤖 Generated with Claude Code

[msoedov]

@Anai-Guo thx for the patch!