refactor(governance): type annotate forbidden emojis and reuse regex pattern

src/va_agent/governance.py

@@ -4,7 +4,7 @@
 import json
 import logging
 import re
-from typing import Literal
+from typing import Literal, cast
 
 from google.adk.agents.callback_context import CallbackContext
 from google.adk.models import LlmRequest, LlmResponse
@@ -22,7 +22,7 @@ from .config import settings
 logger = logging.getLogger(__name__)
 
 
-FORBIDDEN_EMOJIS = [
+FORBIDDEN_EMOJIS: list[str] = [
     "🥵",
     "🔪",
     "🎰",
@@ -144,11 +144,18 @@ Devuelve un JSON con la siguiente estructura:
         person_pattern = r"(?:🧑|👩|👨)"
         tone_pattern = r"[\U0001F3FB-\U0001F3FF]?"
 
+        emoji_separator: str = "|"
+        sorted_emojis = cast(
+            "list[str]", sorted(FORBIDDEN_EMOJIS, key=len, reverse=True)
+        )
+        escaped_emojis = [re.escape(emoji) for emoji in sorted_emojis]
+        emoji_pattern = emoji_separator.join(escaped_emojis)
+
         # Unique pattern that combines all forbidden emojis, including skin tones and compound emojis
         return re.compile(
             rf"{person_pattern}{tone_pattern}\u200d❤️?\u200d💋\u200d{person_pattern}{tone_pattern}"  # kissers
             rf"|{person_pattern}{tone_pattern}\u200d❤️?\u200d{person_pattern}{tone_pattern}"  # lovers
-            rf"|{'|'.join(map(re.escape, sorted(FORBIDDEN_EMOJIS, key=len, reverse=True)))}"  # simple emojis
+            rf"|{emoji_pattern}"  # simple emojis
             rf"|🖕{tone_pattern}"  # middle finger with all skin tone variations
         )