Removes the legacy tailnet v1 API tables (`tailnet_clients`, `tailnet_agents`, `tailnet_client_subscriptions`) and their associated queries, triggers, and functions. These were superseded by the v2 tables (`tailnet_peers`, `tailnet_tunnels`) in migration 000168, and the v1 API code was removed in commit d6154c4310, but the database artifacts were never cleaned up.
**Changes:**
- New migration `000410_remove_tailnet_v1_tables` to drop the unused tables
- Removed 11 unused queries from `tailnet.sql`
- Removed associated manual wrapper methods in `dbauthz` and `dbmetrics`
- ~930 lines deleted across 11 files
Spike Curtis
f47f89d997