Merge origin/master (v0.5.91) into gitea/new_feature

Resolve conflicts:
- streamingHandler.js: adopt upstreamResponseHeaders while keeping 0-token detail row avoidance
- capabilities.js: preserve user-asserted caps and globalThis slots without local caching of catalogSource
- AddCustomModelModal.js & providers/[id]/page.js: wire STT transport marker with custom model edits/assertions
- models/custom/route.js & aliasRepo.js: persist custom model transport and invalidate user caps
- usageRepo.js: key byApiKey live stats by full API key and keep tail in maskApiKey
- UsageStats.js: lazy load charts dynamically

open-sse/handlers/chatCore.js

@@ -9,6 +9,7 @@ import { createRequestLogger } from "../utils/requestLogger.js";
 import { getModelTargetFormat, getModelSupportedFormats, getModelStrip, getModelUpstreamId, getModelType, PROVIDER_ID_TO_ALIAS } from "../config/providerModels.js";
 import { PROVIDERS } from "../config/providers.js";
 import { createErrorResult, parseUpstreamError, formatProviderError } from "../utils/error.js";
+import { upstreamResponseHeaders } from "../utils/upstreamHeaders.js";
 import { HTTP_STATUS, TOKEN_SAVER_HEADER } from "../config/runtimeConfig.js";
 import { handleBypassRequest } from "../utils/bypassHandler.js";
 import { trackPendingRequest, saveRequestDetail } from "@/lib/usageDb.js";
@@ -493,7 +494,7 @@ export async function handleChatCore({ body, modelInfo, credentials, log, onCred
       log.errorLine(reqTag, "✗", `ERROR ${statusCode} · ${provider}/${model} · ${Date.now() - requestStartTime}ms${urlStr}\n    ${errMsg}`);
     }
     reqLogger.logError(new Error(message), finalBody || translatedBody);
-    return createErrorResult(statusCode, errMsg, resetsAtMs);
+    return createErrorResult(statusCode, errMsg, resetsAtMs, upstreamResponseHeaders(providerResponse.headers));
   }
 
   const appendLog = () => {}; // request log derived from usageHistory; kept as no-op seam for handlers