Fix/install slack client (#289)

* Fix #238: Filter system messages in Slack channel analysis

This commit addresses issue #238 by filtering out system messages like 'user joined the channel' notifications and empty messages before sending data to the LLM for analysis. This improves the quality of analysis results in channels that primarily contain system messages rather than actual conversation content.

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Co-Authored-By: Claude <[email protected]>

* fix module dependencies

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Co-authored-by: Claude <[email protected]>

Author: halsk

backend/scripts/run_analysis.py

@@ -33,6 +33,7 @@
 
 from app.models.integration import Integration
 from app.models.reports.cross_resource_report import CrossResourceReport, ResourceAnalysis
+from app.models.reports import AnalysisType
 from app.models.slack import SlackChannel, SlackMessage, SlackUser, SlackWorkspace
 from app.services.analysis.slack_channel import SlackChannelAnalysisService
 from app.services.llm.openrouter import OpenRouterService