feat: add .obo conventions on sql files

[ditadi]

Summary

• Replace asUser API option with .obo.sql file naming convention for user-scoped query execution
• Simplify analytics endpoints from two routes to one unified route
• Remove asUser prop from all UI components (hooks, charts, tables)

Details

Convention-based execution context

Query execution context is now determined by file naming:

• config/queries/<query_key>.sql → Executes as service principal (shared cache)
• config/queries/<query_key>.obo.sql → Executes as user (OBO = On-Behalf-Of, per-user cache)

This is more declarative than passing asUser: true through the UI layer, as the query file itself declares its execution semantics.

API changes

Removed:

• POST /api/analytics/users/me/query/:query_key
• GET /api/analytics/users/me/arrow-result/:jobId
• asUser option from useAnalyticsQuery, useChartData, TableWrapper, and chart components

Unchanged:

• POST /api/analytics/query/:query_key (now handles both contexts)
• GET /api/analytics/arrow-result/:jobId
• Plugin.asUser(req) method (still available for custom plugins)

Cache behavior

• .sql queries use global cache key (shared across all users)
• .obo.sql queries use per-user cache key (isolated per user)

Test plan

• Verify .sql queries execute as service principal
• Verify .obo.sql queries execute as user
• Verify cache isolation between .sql and .obo.sql queries
• Verify global cache sharing for .sql queries across users
• Verify per-user cache isolation for .obo.sql queries
• Run pnpm typecheck - no type errors
• Run pnpm test - all tests pass

[pkosiec]

Could you please add a sentence about the .obo extension in the docs? docs/docs/plugins.md#analytics-plugin