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/streamingHandler.js

@@ -20,6 +20,7 @@ import {
 import { streamStatusForContent } from "../../utils/streamErrorPatterns.js";
 import { saveRequestDetail } from "@/lib/usageDb.js";
 import { SSE_HEADERS_CORS as SSE_HEADERS } from "../../utils/sseConstants.js";
+import { upstreamResponseHeaders } from "../../utils/upstreamHeaders.js";
 
 // Codex returns Responses API SSE → which client format to translate INTO, by request sourceFormat.
 // Gemini-family all map to ANTIGRAVITY decoder; unknown sources fall back to OPENAI.
@@ -158,7 +159,12 @@ export async function handleStreamingResponse({ providerResponse, provider, mode
 
 	return {
 		success: true,
-		response: new Response(transformedBody, { headers: SSE_HEADERS }),
+		response: new Response(transformedBody, {
+			headers: {
+				...SSE_HEADERS,
+				...upstreamResponseHeaders(providerResponse.headers),
+			},
+		}),
 	};
 }