feat(proxy-fitness): egress geo probe + unstable detection + state sweeper

Background probe fetches ipinfo through each pool itself (provider-agnostic
transport), fills an egress IP/country cache (TTL 1h, 8-IP history) and flags
flapping relays as unstable. Periodic state sweeper (10 min) prunes expired
fitness marks, stale geo/ip-history and Freebuff session/cooldown state;
schedulers skip non-server runtimes. Unit tests for the geo cache.

src/shared/services/initializeApp.js

@@ -118,6 +118,16 @@ async function runHeavyStartup() {
   import("@/sse/services/backgroundTokenRefresh.js")
     .then(({ startBackgroundTokenRefresh }) => startBackgroundTokenRefresh())
     .catch((e) => console.log("[BackgroundTokenRefresh] scheduler start failed:", e.message));
+
+  // Pool egress geo probe — fills the Proxy Fitness / Proxy Pools egress column.
+  import("@/lib/network/poolEgressProbe.js")
+    .then(({ startPoolEgressProbe }) => startPoolEgressProbe())
+    .catch((e) => console.log("[PoolEgressProbe] scheduler start failed:", e.message));
+
+  // Periodic in-memory state sweeper — prunes expired fitness/geo/session state.
+  import("@/lib/network/stateSweeper.js")
+    .then(({ startStateSweeper }) => startStateSweeper())
+    .catch((e) => console.log("[StateSweeper] scheduler start failed:", e.message));
 }
 
 function hasQuotaAutoPingEnabled(settings) {