Fix missing ClickHouse cost calculation functions for /metrics endpoint

[devin-ai-integration]

📥 Pull Request

📘 Description

Fixes 500 Internal Server Error on /metrics endpoint caused by missing ClickHouse functions calculate_prompt_cost and calculate_completion_cost. Since ClickHouse doesn't support user-defined functions via CREATE FUNCTION, this PR replaces the function calls with inline multiIf expressions that calculate costs directly in the SQL queries.

Key Changes:

• Replaced calculate_prompt_cost() and calculate_completion_cost() function calls with inline multiIf expressions in metrics.py and traces.py
• Added pricing for major LLM providers: OpenAI (GPT-4, GPT-4o, GPT-3.5), Anthropic (Claude-3), Google (Gemini), and Meta (Llama)
• Includes fallback logic for unknown models (returns 0.0)
• Removed unsupported CREATE FUNCTION statements from migration file

🧪 Testing

• Verified ClickHouse multiIf syntax works correctly with direct query testing
• Confirmed /metrics endpoint no longer returns ClickHouse function errors (now returns authentication errors, indicating the function issue is resolved)
• Ran end-to-end test with AgentOps tracing to ensure overall system functionality remains intact
• Generated successful trace: http://localhost:3000/sessions?trace_id=0a8f158f78c315a6bd5ac15e29a977bc

⚠️ Review Notes

• Pricing Accuracy: Please verify the hardcoded pricing rates against current LLM provider pricing
• Code Duplication: Cost calculation logic is now duplicated across metrics.py and traces.py - consider centralizing in the future
• Unrelated Changes: This PR includes formatting changes in test files that should ideally be in a separate commit
• Maintenance: Adding new models or updating pricing will now require changes in multiple locations

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Link to Devin session: https://app.devin.ai/sessions/c94d96bbaff245c189372484a6eeb193
Requested by: @areibman (Alex)

[devin-ai-integration]

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[devin-ai-integration]

Closing PR as requested - checking updated main branch for new ClickHouse migrations that include cost calculation functions