feat: add /v1 prefix to all API routes

[shefeek-jinnah]

#137

Description

Add /v1 prefix to all API route constants so runtimedb natively serves versioned paths. This allows the Envoy gateway to stop rewriting /v1/* → /* before forwarding, simplifying the routing config.

/health is intentionally excluded since it's used by Kubernetes probes and is an infrastructure concern, not a versioned API endpoint.

Routes updated

• /query → /v1/query
• /information_schema → /v1/information_schema
• /refresh → /v1/refresh
• /connections → /v1/connections
• /connections/{id} → /v1/connections/{id}
• /connections/{id}/health → /v1/connections/{id}/health
• /connections/{id}/cache → /v1/connections/{id}/cache
• /connections/{id}/tables/{schema}/{table}/cache → /v1/connections/{id}/tables/{schema}/{table}/cache
• /secrets → /v1/secrets
• /secrets/{name} → /v1/secrets/{name}
• /query-runs → /v1/query-runs
• /results → /v1/results
• /results/{id} → /v1/results/{id}

Unchanged (already had /v1)

• /v1/files
• /v1/datasets
• /v1/datasets/{id}
• /v1/saved-queries and related endpoints