web/api: show agent versions on device detail page

[nikw9944]

Summary of Changes

• Register controller_agent_versions as external remote table proxies for mainnet-beta, devnet, and testnet environments
• Display telemetry agent, config agent, and controller versions on the device detail page (/dz/devices/<pk>), querying fact_dz_device_link_latency_sample_header for telemetry and the new controller_agent_versions proxy table for config agent/controller versions
• Companion to controller: write config agent version info to ClickHouse doublezero#3578 which adds the controller_agent_versions ReplacingMergeTree table to the controller

Diff Breakdown

Category	Files	Lines (+/-)	Net
Core logic	3	+69 / -0	+69
Scaffolding	1	+3 / -0	+3
Total	4	+72 / -0	+72

Small feature — API queries + frontend display with scaffolding for remote table registration.

Key files (click to expand)

• api/handlers/devices.go — Add version fields to DeviceDetail struct; query telemetry agent version from latency sample headers and config agent/controller version from controller_agent_versions proxy table
• web/src/components/device-detail-page.tsx — Show telemetry agent, config agent, and controller version cards on device detail page
• web/src/lib/api.ts — Add version fields to DeviceDetail TypeScript interface
• admin/remotetables/setup.go — Register controller_agent_versions proxy tables for all three environments

ClickHouse Grants

The Lake remote user needs SELECT on the new table in each environment (one-time manual grant):

GRANT SELECT ON "mainnet-beta".controller_agent_versions TO <lake_remote_user>;
GRANT SELECT ON devnet.controller_agent_versions TO <lake_remote_user>;
GRANT SELECT ON testnet.controller_agent_versions TO <lake_remote_user>;

Testing Verification

• All existing device handler tests pass (16/16), including TestGetDevice_ReturnsDetails, TestGetDevice_IncludesContributorInfo, TestGetDevice_IncludesTrafficRates
• Version queries are non-fatal — if the proxy table doesn't exist yet or the device has no version data, the fields are simply omitted from the response