perf(db): add missing indexes for high-frequency queries

[lancy]

Summary

• Add 4 new database indexes to optimize query performance for high-frequency operations
• Add schema-defined indexes in Drizzle following existing patterns (runner_job_queue, agent_schedules)

Indexes Added

Index	Table	Type	Purpose
idx_agent_runs_user_created	agent_runs	Composite	User run listing with time-based sorting
idx_agent_runs_running_heartbeat	agent_runs	Partial	Cron cleanup job (only running status)
idx_agent_runs_schedule_created	agent_runs	Partial	Schedule run history (only scheduled runs)
idx_agent_sessions_user_compose_artifact	agent_sessions	Composite	findOrCreate pattern optimization

Query Impact

• GET /v1/runs: Now uses composite index instead of full table scan
• /api/cron/cleanup-sandboxes: Uses partial index on running status
• schedule-service.ts getRecentRuns: Uses partial index for scheduled runs
• agent-session-service.ts findOrCreate: Uses composite index

What's NOT Included

• cli_tokens.expiresAt: Not needed - unique index on token already covers auth queries (returns 0-1 rows)

Test plan

• Type check passes (pnpm check-types)
• Lint passes (pnpm turbo run lint)
• All tests pass (pnpm vitest --run)
• Run pnpm db:migrate after deployment to apply indexes

Closes #1284

🤖 Generated with Claude Code

[lancy]

Code Review - Claude Code

Commit: c6a2bb1 - perf(db): add missing indexes for high-frequency queries

Summary

This PR adds 4 database indexes to optimize high-frequency queries. The changes are well-designed and follow best practices.

Files Reviewed

File	Status
migrations/0051_add_performance_indexes.sql	Added
schema/agent-run.ts	Modified
schema/agent-session.ts	Modified

Index Analysis

Index	Type	Purpose	Verdict
idx_agent_runs_user_created	Composite	User run listing with time sort	Well-designed
idx_agent_runs_running_heartbeat	Partial	Cron cleanup for stale sandboxes	Excellent
idx_agent_runs_schedule_created	Partial	Schedule run history	Well-designed
idx_agent_sessions_user_compose_artifact	Composite	findOrCreate pattern	Appropriate

Bad Code Smell Checklist

• No new mocks introduced
• No unnecessary try/catch blocks
• No dynamic imports
• No any types (uses as never for Drizzle partial index syntax - established pattern)
• No lint/type suppressions
• No artificial delays or fake timers
• No hardcoded URLs

Issues Found

None

Verdict

APPROVE - Clean performance optimization with well-documented migrations and appropriate use of partial indexes.

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Detailed review: codereviews/20260116/review-c6a2bb1.md