feat(dashboard): per-key model restrictions, pin header routing, combo side-panel picker

- Endpoint: per-API-key model allowlist (schema v3) enforced on chat (403)
  and /v1/models; Full-access toggle + multi-select picker in Keys UI.
- Providers: honor x-connection-id in /v1/chat/completions — pinned requests
  no longer rotate to another account on failure.
- Providers: strategy saves merge into stored enabled:false override;
  Test All groups match grid sections; 1-by-1 skips disabled connections.
- Dashboard: provider-card toggle syncs from server on failure; grid toggles
  always visible; connection rows get clear-✕ for stale error banners.
- Combo editor: on desktop (xl+) the Add-Model picker opens as a floating
  side panel beside the untouched combo popup instead of stacking on top;
  mobile keeps the full-screen overlay.
- Long API-key overflow fixed in key rows + provider model sections.

open-sse/utils/stream.js

@@ -1,6 +1,6 @@
 import { translateResponse, initState } from "../translator/index.js";
 import { FORMATS } from "../translator/formats.js";
-import { trackPendingRequest, appendRequestLog } from "@/lib/usageDb.js";
+import { trackPendingRequest } from "@/lib/usageDb.js";
 import { extractUsage, mergeUsage, hasValidUsage, estimateUsage, logUsage, addBufferToUsage, filterUsageForFormat, COLORS } from "./usageTracking.js";
 import { parseSSELine, hasValuableContent, fixInvalidId, formatSSE } from "./streamHelpers.js";
 import { getOpenAIResponsesEventName, isOpenAIResponsesTerminalEvent, formatIncompleteOpenAIResponsesStreamFailure } from "./responsesStreamHelpers.js";
@@ -361,10 +361,7 @@ export function createSSEStream(options = {}) {
 
           if (hasValidUsage(usage)) {
             logUsage(provider, usage, model, connectionId, apiKey);
-          } else {
-            appendRequestLog({ model, provider, connectionId, tokens: null, status: "200 OK" }).catch(() => { });
           }
-          
           // IMPORTANT: In passthrough mode we still must terminate the SSE stream.
           // Some clients (e.g. OpenClaw) expect the OpenAI-style sentinel:
           //   data: [DONE]\n\n
@@ -447,13 +444,9 @@ export function createSSEStream(options = {}) {
         if (!hasValidUsage(state?.usage) && totalContentLength > 0) {
           state.usage = estimateUsage(body, totalContentLength, sourceFormat);
         }
-
         if (hasValidUsage(state?.usage)) {
           logUsage(state.provider || targetFormat, state.usage, model, connectionId, apiKey);
-        } else {
-          appendRequestLog({ model, provider, connectionId, tokens: null, status: "200 OK" }).catch(() => { });
         }
-        
         if (onStreamComplete) {
           onStreamComplete({
             content: accumulatedContent,