fix: Remove ModerationResult and unused imports from AI services

Fix ImportError caused by removed ModerationResult class.

Changes:
- Remove ModerationResult from ai/__init__.py exports
- Remove unused ContentCategory enum and parse_categories function
- Remove unused imports from ai_moderation.py
- Clean up NullProvider to only have analyze_image method

Fixes bot startup crash.

src/guardden/cogs/ai_moderation.py

@@ -8,7 +8,6 @@ import discord
 from discord.ext import commands
 
 from guardden.bot import GuardDen
-from guardden.services.ai.base import ContentCategory, ModerationResult
 
 logger = logging.getLogger(__name__)
 

src/guardden/services/ai/__init__.py

@@ -1,6 +1,6 @@
 """AI services for content moderation."""
 
-from guardden.services.ai.base import AIProvider, ModerationResult
+from guardden.services.ai.base import AIProvider, ImageAnalysisResult
 from guardden.services.ai.factory import create_ai_provider
 
-__all__ = ["AIProvider", "ModerationResult", "create_ai_provider"]
+__all__ = ["AIProvider", "ImageAnalysisResult", "create_ai_provider"]

src/guardden/services/ai/base.py

@@ -9,20 +9,6 @@ from enum import Enum
 from typing import Literal, TypeVar
 
 
-class ContentCategory(str, Enum):
-    """Categories of problematic content."""
-
-    SAFE = "safe"
-    HARASSMENT = "harassment"
-    HATE_SPEECH = "hate_speech"
-    SEXUAL = "sexual"
-    VIOLENCE = "violence"
-    SELF_HARM = "self_harm"
-    SPAM = "spam"
-    SCAM = "scam"
-    MISINFORMATION = "misinformation"
-
-
 class NSFWCategory(str, Enum):
     """NSFW content subcategories with increasing severity."""
 
@@ -45,17 +31,6 @@ class RetryConfig:
     max_delay: float = 2.0
 
 
-def parse_categories(values: list[str]) -> list[ContentCategory]:
-    """Parse category values into ContentCategory enums."""
-    categories: list[ContentCategory] = []
-    for value in values:
-        try:
-            categories.append(ContentCategory(value))
-        except ValueError:
-            continue
-    return categories
-
-
 async def run_with_retries(
     operation: Callable[[], Awaitable[_T]],
     *,

src/guardden/services/ai/factory.py

@@ -11,21 +11,11 @@ logger = logging.getLogger(__name__)
 class NullProvider(AIProvider):
     """Null provider that does nothing (for when AI is disabled)."""
 
-    async def moderate_text(self, content, context=None, sensitivity=50):
-        from guardden.services.ai.base import ModerationResult
-
-        return ModerationResult()
-
     async def analyze_image(self, image_url, sensitivity=50):
         from guardden.services.ai.base import ImageAnalysisResult
 
         return ImageAnalysisResult()
 
-    async def analyze_phishing(self, url, message_content=None):
-        from guardden.services.ai.base import PhishingAnalysisResult
-
-        return PhishingAnalysisResult()
-
     async def close(self):
         pass