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/AGENTS.md

@@ -16,7 +16,7 @@ Provider-agnostic SSE engine: one OpenAI-style request → any provider (LLM cha
 - `rtk/` — request token-killer. `index.js` compresses `tool_result` content in-place (OpenAI/Claude/Kiro shapes); `filters/` per-tool compressors + `autodetect.js`; `headroom.js` external compress proxy; `caveman.js` system-prompt injector.
 - `transformer/` — `responsesTransformer.js` (Chat Completions SSE → Codex Responses API SSE), `streamToJsonConverter.js`.
 - `shared/` — cross-provider auth/identity: `clineAuth.js`, `machineId.js`, `qoder/`.
-- `services/` — `model.js`, `provider.js`, `accountFallback.js`, `combo.js`, `compact.js`, `tokenRefresh/`+`tokenRefresh.js`, `oauthCredentialManager.js`, `usage/`, `projectId.js`, `kiroModels.js`/`qoderModels.js`.
+- `services/` — `model.js`, `provider.js`, `accountFallback.js`, `combo.js`, `tokenRefresh/`+`tokenRefresh.js`, `oauthCredentialManager.js`, `usage/`, `projectId.js`, `kiroModels.js`/`qoderModels.js`.
 - `utils/` — streamHandler, stream, sse, error, sessionManager, claudeCloaking, clientDetector, proxyFetch (patches global fetch), cursorProtobuf/cursorChecksum, ollamaTransform.
 
 ## Conventions