Statistics page: the statistics database's size, and a fullness bar on the disk tiles

The server section shows the statistics database's size (with its -wal and -shm) and how many answers the query log holds, linking to the dashboard's Storage panel; the disk tiles get the same bar as the dashboard. GET /stats/server has database {path, bytes, query_log_rows}.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

docs/api.md

@@ -566,7 +566,7 @@ Needs `stats:read`. When statistics are disabled, every endpoint but
 | GET | `/stats/top` | `kind` (name, client, nxdomain, servfail, refused, blocked, blocked_client), `since`, `limit` (default 20) | `[{key, count}]`; client, refused and blocked_client entries add `name`, the host name of Jarl's record for the address (the summary's client list too) |
 | GET | `/stats/heatmap` | `since` (default 28d), `key` (default queries) | `{key, from, avg[7][24], samples[7][24]}`, Monday first, local time, `-1` = no data |
 | GET | `/stats/explore` | `?client=&name=&domain=&view=&type=&rcode=&blocked=yes\|no\|LIST&since=24h&views=` | The query log for a filter ([stats.md](stats.md#exploring)): `total`, `blocked`, `series` (per `step` seconds: `t`, `count`, `blocked`), `by` (top 15 of each dimension the filter leaves open: client, name, view, type, rcode, blocked; clients with `name`), `recent` (latest 100: ts, client, client_name, view, name, type, rcode, blocked), `oldest`, `retention`, `client_name`. 404 `query_log_off` without a query log |
-| GET | `/stats/server` | | `{server: {rss, mem_in_use, cpu_percent, threads, pid, cache_rrsets, cache_mem, sockets_udp, sockets_tcp, recursion_highwater, tcp_highwater, version, boot_time, config_time, host: {mem_total, mem_available, load, cpus, uptime}}, named: {recursive_clients, tcp_clients, zones, cpus, worker_threads}, disks: [{path, holds, total, free}]}`; gauges over time: `/stats/timeline?key=g:named:rss` (averages, -1 without a sample) |
+| GET | `/stats/server` | | `{server: {rss, mem_in_use, cpu_percent, threads, pid, cache_rrsets, cache_mem, sockets_udp, sockets_tcp, recursion_highwater, tcp_highwater, version, boot_time, config_time, host: {mem_total, mem_available, load, cpus, uptime}}, named: {recursive_clients, tcp_clients, zones, cpus, worker_threads}, disks: [{path, holds, total, free}], database: {path, bytes, query_log_rows}}`; gauges over time: `/stats/timeline?key=g:named:rss` (averages, -1 without a sample) |
 | GET | `/stats/breakdown` | `group` (qtype, rcode, view, zone, answer, transport, rtt, dnssec, cache, ratelimit, blocklist), `since` | `[{key, count}]` |
 
 ```sh