feat(proxy): otomatik Floxy→DataImpulse failover (decode regresyonu)

Floxy residential proxy bitince/çökünce (402 bakiye veya tünel reddi —
ERR_TUNNEL_CONNECTION_FAILED), EMEX + pcat decode istekleri ölü proxy'ye
çarpıp decode başarı oranını çökertiyordu (2026-06-13: ~17k tünel hatası/24s,
decode %78→%45). Önceki "DataImpulse last-ditch fallback" tarayıcı yolunda hiç
yoktu ve HTTP yolunda her istekte 2 ölü Floxy denemesi ziyan ediyordu.

Paylaşılan ProxyHealthService kapısı (in-memory cooldown): herhangi bir tüketici
bir Floxy bağlantı hatası görünce kapıyı tetikler; cooldown boyunca TÜM tüketiciler
DataImpulse'a düşer. Floxy'den ilk başarılı yanıt veya cooldown bitişi kapıyı
temizler (kendi kendini iyileştirir, periyodik yeniden-deneme). FLOXY_FAILOVER_COOLDOWN_MS
ile ayarlanır (varsayılan 180s).

Bağlanan tüketiciler:
- EMEX HTTP (fetchEmexHtml): kapı açıkken DataImpulse-öncelikli zamanlama
- EMEX tarayıcı (Playwright): launch'ta dinamik sağlayıcı seçimi + ensureSession
  health-gate'i (Floxy ölünce DataImpulse'a relaunch, kapı temizlenince Floxy'i
  yeniden dene); scrape-içi tünel ölümünde tripFloxyFailover
- pcat (buildProxy): hem call hem capture (Playwright JWT) bacakları DataImpulse'a düşer

isProxyConnectFailure(): yalnız gerçek bağlantı hatalarında tetikler — yavaş-ama-
canlı exit'in nav timeout'u failover'ı tetiklemez.

Test: ProxyHealthService + isProxyConnectFailure birim testleri; tüm api suite (303) yeşil.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

apps/api/src/integrations/emex/emex.service.ts

@@ -23,9 +23,11 @@ import { ProxyAgent } from "undici";
 import { isBackfillContext } from "../../jobs/prefetch-context";
 import { PostHogService } from "../../posthog/posthog.service";
 import { RedisService } from "../../redis/redis.service";
+import { ProxyHealthService } from "../proxy-telemetry/proxy-health.service";
 import {
   ProxyTelemetryService,
   classifyTransportError,
+  isProxyConnectFailure,
 } from "../proxy-telemetry/proxy-telemetry.service";
 import { parseUnitLeaves, parseVehicleTree } from "./emex-tree.parser";
 import { EmexBrowserService } from "./emex.browser";
@@ -147,6 +149,7 @@ export class EmexService {
     private redis: RedisService,
     private posthog: PostHogService,
     private proxyTelemetry: ProxyTelemetryService,
+    private proxyHealth: ProxyHealthService,
   ) {
     // __dirname is apps/api/src/integrations/emex/ or dist/integrations/emex/
     // Scraper lives at <monorepo-root>/scripts/emex-vin-scraper.js
@@ -383,8 +386,14 @@ export class EmexService {
     // and a different proxy IP must not "retry" it away.
     const schedule: Array<"dataimpulse" | "floxy"> = [];
     if (this.emexProxyProvider === "floxy") {
-      if (this.emexFloxy) schedule.push("floxy", "floxy");
-      if (this.emexProxy) schedule.push("dataimpulse");
+      if (this.emexFloxy && this.proxyHealth.isFloxyDown() && this.emexProxy) {
+        // Floxy gate tripped → DataImpulse-first (rotating ports cover its ~50%
+        // dead ports), with one Floxy probe last so a recovery is still detected.
+        schedule.push("dataimpulse", "dataimpulse", "floxy");
+      } else {
+        if (this.emexFloxy) schedule.push("floxy", "floxy");
+        if (this.emexProxy) schedule.push("dataimpulse");
+      }
     } else if (this.emexProxyProvider === "dataimpulse") {
       if (this.emexProxy) schedule.push("dataimpulse", "dataimpulse", "dataimpulse");
       if (this.emexFloxy) schedule.push("floxy", "floxy");
@@ -417,6 +426,7 @@ export class EmexService {
           throw new Error(`EMEX HTTP ${res.status} for ${url}`);
         }
         if (provider === "floxy") {
+          this.proxyHealth.reportFloxySuccess(); // Floxy answered — clear cooldown
           this.logger.log(`EMEX fetch via Floxy fallback succeeded for ${url}`);
         }
         return await res.text();
@@ -446,6 +456,11 @@ export class EmexService {
             /fetch failed|ECONNRESET|ECONNREFUSED|EAI_AGAIN|socket hang up|other side closed|terminated|UND_ERR/i.test(
               `${e.message} ${String(e.cause ?? "")}`,
             ));
+        // A Floxy connect failure (dead exit / tunnel refused) trips the shared
+        // gate so EMEX + pcat fail over to DataImpulse for the cooldown window.
+        if (provider === "floxy" && isProxyConnectFailure(e)) {
+          this.proxyHealth.reportFloxyFailure(`emex http: ${classifyTransportError(e)}`);
+        }
         if (!transient || attempt === maxAttempts) break;
         // A Floxy transport failure means the current sticky exit IP is dead —
         // roll to a fresh session so the next Floxy attempt gets a new IP.
@@ -909,6 +924,12 @@ export class EmexService {
     } catch (error) {
       const err = error as Error;
 
+      // Floxy tunnel dead mid-scrape → trip failover so the next acquirePage
+      // re-establishes the session on DataImpulse.
+      if (isProxyConnectFailure(err)) {
+        void this.browserService.tripFloxyFailover(`emex decode: ${classifyTransportError(err)}`);
+      }
+
       if (
         err instanceof BadRequestException ||
         err instanceof ServiceUnavailableException ||
@@ -1052,6 +1073,10 @@ export class EmexService {
       return { parts: [], schemaImageUrl: null, hotspots: [], schemaWidth: 0, schemaHeight: 0 };
     } catch (error) {
       const err = error as Error;
+      // Floxy tunnel dead mid-scrape → trip failover for the next acquirePage.
+      if (isProxyConnectFailure(err)) {
+        void this.browserService.tripFloxyFailover(`emex parts: ${classifyTransportError(err)}`);
+      }
       this.logger.error(`Failed to fetch category parts: ${err.message}`);
       return { parts: [], schemaImageUrl: null, hotspots: [], schemaWidth: 0, schemaHeight: 0 };
     } finally {