Avoid lifecycle history scans in fleet snapshots

src/lib/server/fleet/overview.ts

@@ -34,11 +34,18 @@ export function fleetOperations(now = Date.now()): FleetOperation[] {
             href: `/campaigns/${encodeURIComponent(row.id)}` });
     }
     // Only the newest lifecycle operation can still require action on a server.
-    const lifecycle = handle.prepare(`SELECT d.* FROM server_deployments d
-        WHERE d.server_deleted_at IS NULL AND (d.state IN ('queued', 'running', 'waiting', 'awaiting-health')
-        OR (d.state IN ('done', 'warning', 'cancelled') AND d.finished_at >= ?)
-        OR (d.state IN ('failed', 'interrupted', 'warning') AND NOT EXISTS
-            (SELECT 1 FROM server_deployments n WHERE n.server = d.server AND n.rowid > d.rowid)))`)
+    // Separate branches let SQLite use state and finish indexes; UNION deduplicates
+    // recent warnings that are also the newest operation. Unary + keeps terminal
+    // branches on finished_at and rowid instead of searching historical states.
+    const lifecycle = handle.prepare(`SELECT id, server, action, state, stage, error, started_at FROM server_deployments
+        WHERE server_deleted_at IS NULL AND state IN ('queued', 'running', 'waiting', 'awaiting-health')
+        UNION
+        SELECT id, server, action, state, stage, error, started_at FROM server_deployments
+        WHERE server_deleted_at IS NULL AND +state IN ('done', 'warning', 'cancelled') AND finished_at >= ?
+        UNION
+        SELECT id, server, action, state, stage, error, started_at FROM server_deployments
+        WHERE server_deleted_at IS NULL AND +state IN ('failed', 'interrupted', 'warning')
+            AND rowid IN (SELECT MAX(rowid) FROM server_deployments GROUP BY server)`)
         .all(since) as { id: string; server: string; action: string; state: string; stage: string;
             error: string | null; started_at: string }[];
     for (const row of lifecycle) {