security: integrate SHIELD jailbreak/crisis detection

Integrate SHIELD (Sovereign Harm Interdiction & Ethical Layer Defense) into
Hermes Agent pre-routing layer for comprehensive jailbreak and crisis detection.

SHIELD Features:
- Detects 9 jailbreak pattern categories (GODMODE dividers, l33tspeak, boundary
  inversion, token injection, DAN/GODMODE keywords, refusal inversion, persona
  injection, encoding evasion)
- Detects 7 crisis signal categories (suicidal ideation, method seeking,
  l33tspeak evasion, substance seeking, despair, farewell, self-harm)
- Returns 4 verdicts: CLEAN, JAILBREAK_DETECTED, CRISIS_DETECTED,
  CRISIS_UNDER_ATTACK
- Routes crisis content ONLY to Safe Six verified models

Safety Requirements:
- <5ms detection latency (regex-only, no ML)
- 988 Suicide & Crisis Lifeline included in crisis responses

Addresses: Issues #72, #74, #75

tools/shield/__init__.py

@@ -0,0 +1,44 @@
+"""
+SHIELD Security Module for Hermes
+
+Jailbreak and Crisis Detection System
+Based on Issue #75 Red Team Audit Specifications
+
+Usage:
+    from hermes.shield import detect, ShieldDetector, Verdict
+    from hermes.shield import is_safe_six_model, get_crisis_prompt
+    
+    # Simple detection
+    result = detect("user message")
+    
+    # Advanced usage
+    detector = ShieldDetector()
+    result = detector.detect("user message")
+    
+    if result['verdict'] == Verdict.CRISIS_DETECTED.value:
+        # Use crisis prompt
+        crisis_prompt = get_crisis_prompt()
+"""
+
+from hermes.shield.detector import (
+    ShieldDetector,
+    Verdict,
+    SAFE_SIX_MODELS,
+    CRISIS_SYSTEM_PROMPT,
+    detect,
+    is_safe_six_model,
+    get_crisis_prompt,
+)
+
+__all__ = [
+    'ShieldDetector',
+    'Verdict',
+    'SAFE_SIX_MODELS',
+    'CRISIS_SYSTEM_PROMPT',
+    'detect',
+    'is_safe_six_model',
+    'get_crisis_prompt',
+]
+
+__version__ = "1.0.0"
+__author__ = "Hermes Security Team"