Add active/inactive/game-time timers to fleet + server pages

Fleet cards and the per-server detail hero now show three live-ticking
timers: Active (since players > 0), Inactive (since server emptied), and
Game (since InitGame in games_sp.log, back-computed from the log's own
MM:SS prefix so it stays accurate across restarts). Anchors are
persisted on `servers` and fanned out via the SSE bus; a single 1s
ticker feeds every card. Idle map cycles are filtered out so the game
timer doesn't flicker.

src/lib/server/db/index.ts

@@ -37,7 +37,12 @@ const SERVERS_COLUMNS: Array<{ name: string; ddl: string }> = [
     { name: 'game_id', ddl: 'ALTER TABLE servers ADD COLUMN game_id TEXT' },
     { name: 'image', ddl: 'ALTER TABLE servers ADD COLUMN image TEXT' },
     { name: 'created_by', ddl: 'ALTER TABLE servers ADD COLUMN created_by TEXT' },
-    { name: 'destroyed_at', ddl: 'ALTER TABLE servers ADD COLUMN destroyed_at TEXT' }
+    { name: 'destroyed_at', ddl: 'ALTER TABLE servers ADD COLUMN destroyed_at TEXT' },
+    // Occupancy + match timers — see schema.sql for semantics.
+    { name: 'active_since', ddl: 'ALTER TABLE servers ADD COLUMN active_since TEXT' },
+    { name: 'inactive_since', ddl: 'ALTER TABLE servers ADD COLUMN inactive_since TEXT' },
+    { name: 'game_started_at', ddl: 'ALTER TABLE servers ADD COLUMN game_started_at TEXT' },
+    { name: 'game_ended_at', ddl: 'ALTER TABLE servers ADD COLUMN game_ended_at TEXT' }
 ];
 
 function migrateServers(handle: Database.Database): void {