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/routes/+page.svelte

@@ -21,6 +21,10 @@
         health: Health;
         endpoint: { host: string; port: number } | null;
         held: HeldRow[];
+        active_since: string | null;
+        inactive_since: string | null;
+        game_started_at: string | null;
+        game_ended_at: string | null;
     }
 
     let servers = $state<ServerRow[]>([]);
@@ -47,7 +51,11 @@
                 roster: fallback.roster,
                 health: fallback.health,
                 lastSeenAt: fallback.last_seen_at,
-                lastError: fallback.last_error
+                lastError: fallback.last_error,
+                activeSince: fallback.active_since,
+                inactiveSince: fallback.inactive_since,
+                gameStartedAt: fallback.game_started_at,
+                gameEndedAt: fallback.game_ended_at
             };
         }
         return {
@@ -57,7 +65,11 @@
             roster: live.roster,
             health: live.health,
             lastSeenAt: live.lastSeenAt,
-            lastError: live.lastError
+            lastError: live.lastError,
+            activeSince: live.activeSince,
+            inactiveSince: live.inactiveSince,
+            gameStartedAt: live.gameStartedAt,
+            gameEndedAt: live.gameEndedAt
         };
     }
 </script>
@@ -91,6 +103,10 @@
                     lastSeenAt={live.lastSeenAt}
                     lastError={live.lastError}
                     held={s.held}
+                    activeSince={live.activeSince}
+                    inactiveSince={live.inactiveSince}
+                    gameStartedAt={live.gameStartedAt}
+                    gameEndedAt={live.gameEndedAt}
                 />
             {/each}
         </div>