fix(server): hata yönetimini iyileştir

Zamanlayıcı ve qbit istemcisi bileşenlerinde hata işleme yeteneklerini
güçlendirir.

- loop.scheduler: qbit hatalarında sistem durumunu ve sağlık bilgisini
  güncelleme ekler.
- qbit.client: geçici ağ hatalarını (EAI_AGAIN vb.) algılayarak oturum
  durumunu sıfırlar.
- timer.worker: global hata yakalama ekleyerek işleyicinin çökmesini
  engeller ve hataları günlüğe kaydeder.

apps/server/src/loop/loop.scheduler.ts

@@ -1,7 +1,7 @@
 import { QbitClient } from "../qbit/qbit.client"
 import { tickLoopJobs } from "./loop.engine"
-import { getStatusSnapshot, refreshJobsStatus, setTorrentsStatus } from "../status/status.service"
+import { getStatusSnapshot, refreshJobsStatus, setQbitStatus, setTorrentsStatus } from "../status/status.service"
-import { emitStatusUpdate } from "../realtime/emitter"
+import { emitQbitHealth, emitStatusUpdate } from "../realtime/emitter"
 import { logger } from "../utils/logger"
 
 export const startLoopScheduler = (qbit: QbitClient, intervalMs: number) => {
@@ -20,7 +20,19 @@ export const startLoopScheduler = (qbit: QbitClient, intervalMs: number) => {
         jobs,
       });
     } catch (error) {
+      const message = error instanceof Error ? error.message : "Unknown error";
       logger.error({ error }, "Loop scheduler tick failed");
+      setQbitStatus({ ok: false, lastError: message });
+      emitQbitHealth({ ok: false, lastError: message });
+      try {
+        const current = await getStatusSnapshot();
+        emitStatusUpdate({
+          ...current,
+          qbit: { ...current.qbit, ok: false, lastError: message },
+        });
+      } catch {
+        // Swallow secondary status errors to keep scheduler alive.
+      }
     }
   }, intervalMs);
 };

apps/server/src/qbit/qbit.client.ts

@@ -48,6 +48,18 @@ export class QbitClient {
       }
       return await fn();
     } catch (error) {
+      if (axios.isAxiosError(error)) {
+        const code = error.code ?? "";
+        const transient =
+          code === "EAI_AGAIN" ||
+          code === "ENOTFOUND" ||
+          code === "ECONNREFUSED" ||
+          code === "ECONNRESET" ||
+          code === "ETIMEDOUT";
+        if (transient) {
+          this.loggedIn = false;
+        }
+      }
       if (
         axios.isAxiosError(error) &&
         (error.response?.status === 401 || error.response?.status === 403)

apps/server/src/timer/timer.worker.ts

@@ -4,6 +4,7 @@ import { readDb, writeDb } from "../storage/jsondb";
 import { TimerLog, TimerSummary } from "../types";
 import { emitTimerLog, emitTimerSummary } from "../realtime/emitter";
 import { nowIso } from "../utils/time";
+import { logger } from "../utils/logger";
 
 const MAX_LOGS = 2000;
 
@@ -17,6 +18,7 @@ const normalizeTags = (tags?: string, category?: string) => {
 
 export const startTimerWorker = (qbit: QbitClient, intervalMs: number) => {
   setInterval(async () => {
+    try {
       const db = await readDb();
       const rules = db.timerRules ?? [];
       if (rules.length === 0) {
@@ -88,5 +90,8 @@ export const startTimerWorker = (qbit: QbitClient, intervalMs: number) => {
         db.timerSummary = summary;
         await writeDb(db);
       }
+    } catch (error) {
+      logger.error({ error }, "Timer worker tick failed");
+    }
   }, intervalMs);
 };