Surface structured RCON failure reasons in the fleet UI

rconGetStatus previously collapsed at least five distinct failure modes
(no password, no port, socket error, timeout, bad reply) into a single
null return, so the UI could only say "rcon unreachable" — useless when
diagnosing a real Alcatraz outage.

Refactored to rconStatusResult() returning a discriminated union with a
RconFailure reason and human-facing detail. The worker persists these as
"<reason>:<detail>" in last_error (no schema change). /api/servers now
returns the derived endpoint (host:port) per server plus a top-level
integrations block (rcon/komodo configured, timeout, default host).

Server detail page gains an RCON diagnostic panel when health is not
online: shows the exact endpoint being dialed, integration status,
timeout, a color-coded reason tag, the detail, and a targeted fix hint.
Wrong-password replies are detected via "bad rcon" text in the print
body.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

src/routes/api/servers/+server.ts

@@ -1,6 +1,7 @@
 import { json } from '@sveltejs/kit';
 import { listServers, heldByBeta } from '$lib/server/fleet/servers.js';
 import { classifyHealth } from '$lib/server/fleet/health.js';
+import { config, komodoConfigured, rconConfigured } from '$lib/server/config.js';
 import type { RconPlayer } from '$lib/server/integrations/rcon.js';
 
 function safeJson<T>(raw: string | null): T | null {
@@ -13,11 +14,23 @@ function safeJson<T>(raw: string | null): T | null {
 }
 
 export async function GET() {
+    const rconHost = config.rcon.host;
     const servers = listServers().map((s) => ({
         ...s,
         roster: safeJson<RconPlayer[]>(s.last_roster),
         health: classifyHealth(s.last_seen_at, s.last_error),
+        // Derived endpoint — same logic as endpointFor() but without asking
+        // Komodo. If we don't have a port yet, endpoint is null.
+        endpoint: s.game_port ? { host: s.rcon_host ?? rconHost, port: s.game_port } : null,
         held: [...heldByBeta(s.name).entries()].map(([target, slug]) => ({ target, slug }))
     }));
-    return json({ servers });
+    return json({
+        servers,
+        integrations: {
+            rcon: rconConfigured(),
+            komodo: komodoConfigured(),
+            rconTimeoutMs: config.rcon.timeoutMs,
+            defaultRconHost: rconHost
+        }
+    });
 }